-- :material-calendar: [Release Notes](release-notes/2024/corporate-memory-24-3/index.md)
+- :material-home: [Home](#what-is-eccenca-corporate-memory)
---
- Documentation of changes and enhancements for each version.
-
-- :material-list-status: [Tutorials](tutorials/index.md)
-
- ---
-
- Learn by example and step-by-step guidelines to achieve a concrete goal fast.
-
-- :material-arrow-right-thick: [Getting Started](getting-started/index.md)
-
- ---
-
- This page describes how to work with Corporate Memory and shortly outlines all functionalities of the user interface.
+ New to eccenca Corporate Memory? Start here: what the product is for, how it is structured, and how to get access.
- :material-star: [Build](build/index.md)
@@ -69,4 +56,156 @@ hide:
Extend Corporate Memory with custom plugins and packages, and access it programmatically through the Python, Java and REST APIs.
+- :material-calendar: [Release Notes](release-notes/2026/corporate-memory-26-2/index.md)
+
+ ---
+
+ Documentation of changes and enhancements for each version.
+
+- :material-list-status: [Tutorials](tutorials/index.md)
+
+ ---
+
+ Learn by example and step-by-step guidelines to achieve a concrete goal fast.
+
+
+## What is eccenca Corporate Memory?
+
+Corporate Memory connects data that lives in separate systems into one meaningful whole, a knowledge graph.
+It keeps that whole usable as the systems and the business around it change.
+
+Prefer to watch?
+The video [eccenca Corporate Memory in 3 minutes](https://www.youtube.com/watch?v=Lb0zpH9oLMM){target=_blank} shows what Corporate Memory is for, without a product demo.
+
+[{ class="bordered off-glb" width="60%" }](https://www.youtube.com/watch?v=Lb0zpH9oLMM){target=_blank}
+
+Reading time: 4 minutes.
+No prior knowledge is required.
+The following sections explain what the product is for, not how to use it.
+
+### A familiar problem
+
+A supplier has just gone out of business.
+Someone in purchasing needs to know which products are affected.
+
+The answer exists.
+But the product is called `P-10045` in the ERP system, `PRD_10045_A` in the PLM system and `45100-XX` in the supplier portal.
+Each system is right on its own terms, and none of them knows about the others.
+So the answer is put together by hand, takes days, and is out of date by the time anyone acts on it.
+
+Most organizations do not have a data shortage.
+They have a connection problem.
+
+### What eccenca Corporate Memory does
+
+{ class="bordered" }
+
+Corporate Memory gives the context of the data a place to live.
+
+It reads data from existing systems and expresses it as a knowledge graph: things, and the named relationships between them.
+This product is made at this plant.
+This plant is supplied by this company.
+Each statement is written down explicitly, in a form both people and software can follow.
+
+The three identifiers do not disappear.
+They become properties of one product, so any fact can be traced back to the system it came from, and written back to it where that makes sense.
+
+The question from purchasing now has a place to be asked, and an answer that is the same for everyone who asks it.
+
+{ class="bordered" width="60%" }
+
+Around the graph, the platform provides what is needed to keep it alive: building it from real sources, exploring and correcting it, checking that it still meets expectations, and serving it to the people and applications that need answers.
+
+- [What is a knowledge graph?](introduction/what-is-a-knowledge-graph/index.md) explains the idea in more depth.
+- [eccenca Corporate Memory at a glance](introduction/corporate-memory-at-a-glance/index.md) shows how the parts of the product fit together.
+
+### Terms used in this documentation
+
+These terms are not needed for this introduction.
+They become useful once reading continues into the other sections.
+
+| Term | In one line |
+| --- | --- |
+| Mapping | How source columns become things and relationships in the graph. |
+| Linking | Deciding when two records from different systems mean the same thing. |
+| Shapes (SHACL) | Writing down what must be true about the data, and checking it. |
+| Vocabulary | The agreed names for the kinds of things and relationships in use. |
+| Workflow | Running all of it again whenever the sources change. |
+| Marketplace | Ready-made packages to install and adapt. |
+| cmemc | Doing the same from the command line, for automation and CI/CD. |
+
+### What it is and what it is not
+
+| Corporate Memory is … | … and it is not |
+| --- | --- |
+| a layer that connects with existing systems | a replacement for them; the ERP system stays the ERP system |
+| built to represent meaning and relationships | a data warehouse or a BI tool for aggregating numbers |
+| configured for business users by people who know the data and the domain | a finished application for end users |
+| support for modeling decisions | a way to avoid them |
+
+It does not wire the systems to each other either.
+Corporate Memory connects with them, brings their data together in one graph, and leaves them running as they are.
+
+The last row matters most.
+Deciding what the data means is modeling work.
+Corporate Memory supports that work, it does not do it.
+
+### Is it the right tool?
+
+Corporate Memory is likely to add value when most of these questions are answered with yes:
+
+- Do the questions cross system boundaries?
+- Is the same real-world thing represented differently in different places?
+- Do relationships matter as much as the values themselves?
+- Is the structure of the data expected to keep changing?
+
+It is probably not the right tool for a single well-structured source with a stable schema, or for a question that is essentially "sum this column by month".
+It is also not the right tool when nobody in the organization is available to decide what the data means.
+That last one is the most common reason such projects stall, and no software solves it.
+
+### Who works with it
+
+
+
+- __Linked Data Experts and data engineers__
+
+ ---
+
+ Do most of the building: connect sources, model, and keep the graph current.
+
+ [:octicons-arrow-right-24: Build a knowledge graph](build/index.md)
+
+- __Business users__
+
+ ---
+
+ Work with what has been configured for them, usually without seeing the model behind it.
+
+ [:octicons-arrow-right-24: Explore and manage knowledge](explore-and-author/index.md)
+
+- __Developers__
+
+ ---
+
+ Integrate Corporate Memory with other applications and extend it.
+
+ [:octicons-arrow-right-24: Extend Corporate Memory](develop/index.md)
+
+- __Administrators__
+
+ ---
+
+ Install, operate and upgrade it.
+
+ [:octicons-arrow-right-24: Deploy and operate](deploy-and-configure/index.md)
+
+
+
+Choosing one of these roles is not required at this point.
+
+### Next
+
+- [What is a knowledge graph?](introduction/what-is-a-knowledge-graph/index.md): the concept, 5 minutes, on the main path
+- [Semantic Web basics](introduction/semantic-web-basics/index.md): optional, the terminology, about 35 minutes
+- [eccenca Corporate Memory at a glance](introduction/corporate-memory-at-a-glance/index.md): the parts of the product and how they relate
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+---
+nav:
+ - "What is a knowledge graph?": what-is-a-knowledge-graph
+ - Semantic Web basics: semantic-web-basics
+ - At a glance: corporate-memory-at-a-glance
+ - Get access: get-access
+ - See it in the product: see-it-in-the-product
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+---
+title: "Introduction: eccenca Corporate Memory at a glance"
+---
+
+# eccenca Corporate Memory at a glance
+
+[What is a knowledge graph?](../what-is-a-knowledge-graph/index.md) explains the knowledge graph in the middle of the following picture.
+The five areas around it are where the work with that graph happens.
+Each area is a part of eccenca Corporate Memory, and each has its own section in this documentation.
+The following descriptions say what each one is for, in two or three sentences, and nothing about how to use it.
+
+{ width="80%" }
+
+## Build
+
+Build is where data becomes a knowledge graph.
+A source is connected: a file, a database, an API.
+Its columns are then defined as things and relationships, and the Mapping Creator proposes most of that.
+Workflows put the steps in order, so the graph can be rebuilt whenever the sources change.
+
+Mostly used by Linked Data Experts and data engineers.
+
+[:octicons-arrow-right-24: Go to Build](../../build/index.md)
+
+## Explore
+
+Explore is where people work with the graph.
+Searching finds a thing, its connections become visible, and what is wrong is corrected in place, without a query language.
+Views can be tailored to a task, so a colleague sees their own fields rather than the model behind them.
+
+Used by business users and Linked Data Experts.
+
+[:octicons-arrow-right-24: Go to Explore](../../explore-and-author/index.md)
+
+## Consume
+
+Consume is where other systems take over.
+Dashboards, applications, automated processes and AI agents read the same graph through standard interfaces such as SPARQL, SQL and REST.
+Everyone then works from the same answer instead of a copy of their own.
+
+Used by developers, analysts and Linked Data Experts.
+
+[:octicons-arrow-right-24: Go to Consume](../../consume/index.md)
+
+## Govern
+
+Govern is what keeps the whole thing dependable.
+Access rules decide who sees and changes what, and metrics and logs show whether the system is healthy.
+Everything that can be done by hand can also be done from the command line or through an API.
+That is what makes automation and continuous delivery possible.
+
+Used by administrators and operations teams.
+
+[:octicons-arrow-right-24: Go to Automate](../../automate/index.md) · [:octicons-arrow-right-24: Go to Deploy and Configure](../../deploy-and-configure/index.md)
+
+## Distribute
+
+Distribute is how work gets reused.
+The Marketplace holds ready-made content that can be added to an instance: vocabularies, taxonomies, data graphs, Build projects and query catalogs.
+Complete demo and solution setups are included.
+Everything arrives as a versioned package, and Corporate Memory puts its contents where they belong.
+Solutions built in house can be packaged and shared the same way.
+
+Used by Linked Data Experts and developers.
+
+[:octicons-arrow-right-24: Go to Distribution](../../distribution/index.md)
+
+## What else it can do
+
+The five areas above are where most work happens.
+The following capabilities exist alongside them, and are named here so that they are known to exist rather than explained.
+
+| Capability | In one line | Where |
+| --- | --- | --- |
+| Query and SPARQL | The query language for graphs, and the precise way to ask the data a question nobody planned for. | [Queries](../../explore-and-author/query-module/index.md) |
+| Reasoning | Derives the facts that follow from the data and the rules, without anyone stating them. | [Reason](../../build/reference/customtask/cmem_plugin_reason-plugin_reason-ReasonPlugin.md) |
+| Shapes (SHACL) | Record what must be true about the data, and check whether it is. | [Building a customized user interface](../../explore-and-author/graph-exploration/building-a-customized-user-interface/index.md) |
+| Linking rules | Decide when two records from different systems mean the same real-world thing. | [Link Rules](../../explore-and-author/link-rules/index.md) |
+| Link learning | Proposes those rules from examples, instead of requiring them to be written by hand. | [Active Learning](../../build/active-learning/index.md) |
+| Python plugins | Add functions that the standard product does not provide. | [Python Plugins](../../develop/python-plugins/index.md) |
+| Deployment | The technical operating layer, so Corporate Memory runs in different environments. | [Deploy and Configure](../../deploy-and-configure/index.md) |
+
+## Next
+
+- [Get access](../get-access/index.md): a sandbox or an existing instance
+- Basic, the hands-on path to a first knowledge graph in about four hours, is in preparation.
+ Until then, the [Tutorials](../../tutorials/index.md) cover the first steps.
+
+
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+---
+title: "Introduction: Get access to the sandbox"
+---
+
+# Get access to the sandbox
+
+The eccenca Corporate Memory sandbox is a free, personal Corporate Memory instance for trying out the product.
+It is provided at [eccenca.my](https://eccenca.my/) as the Community Edition sandbox.
+
+The following steps register an account at eccenca.my and sign in to the sandbox.
+The result is a running sandbox that serves as the starting point for the tutorials in this documentation.
+
+For the content that a new sandbox includes, and for its limitations, see [Welcome to your eccenca Corporate Memory Sandbox](../../getting-started/with-your-sandbox/index.md).
+
+!!! info "Existing instance"
+
+ With access to an existing Corporate Memory instance, no registration is needed.
+ Open the URL of the instance and sign in with the credentials provided by its administrator, as described in [Login and Logout](../../getting-started/index.md#login-and-logout).
+
+## Prerequisites
+
+The following items are required:
+
+- An email address that receives the messages from eccenca.my
+- A supported web browser, as listed under [Minimal requirements](../../getting-started/index.md#minimal-requirements)
+
+## Register an account
+
+1. Open [eccenca.my](https://eccenca.my/) in a web browser.
+2. Click **GET STARTED**.
+ The eccenca.my sign-in form opens.
+3. Click **Register**.
+ The **Register** form opens.
+4. Enter the following values:
+
+ - **First name:** the first name of the account holder
+ - **Last name:** the last name of the account holder
+ - **Email:** the email address that is used to sign in
+ - **Password:** a password for the account
+ - **Confirm password:** the same password again
+
+ { class="bordered" width="50%" }
+
+5. Click **REGISTER**.
+ The **Terms and Conditions** dialog opens.
+ It covers the eccenca.my terms of service, the data privacy policy and the Ontotext GraphDB Free license agreement.
+
+ { class="bordered" width="50%" }
+
+6. Click **ACCEPT**.
+ The **Email verification** form opens, and eccenca.my sends an email with instructions to verify the email address.
+
+ { class="bordered" width="50%" }
+
+7. Follow the instructions in the email to verify the email address.
+ The account is activated, and the **Your Sandboxes** overview opens.
+
+## Request a sandbox
+
+1. In the **Your Sandboxes** overview, click **Request Sandbox**.
+
+ { class="bordered" width="50%" }
+
+2. Enter a name of choice for the instance in the form.
+
+The provisioning of the sandbox takes up to 24 hours.
+When the sandbox is ready, eccenca.my sends an email with the link to the sandbox and its credentials.
+
+## Open the sandbox
+
+1. Open the link from the email that announces the sandbox.
+2. Sign in with the credentials from the same email.
+
+## Next
+
+- [See it in the product](../see-it-in-the-product/index.md): five features, with the documentation for each
+- Basic, the guided path from a source file to a knowledge graph in about four hours, is in preparation.
+ Until then, the [Tutorials](../../tutorials/index.md) cover the first steps.
+
+
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+---
+title: "Introduction: See it in the product"
+---
+
+# See it in the product
+
+The five features below are the ones a newcomer to eccenca Corporate Memory meets first.
+Each is shown once, with a link to the documentation that covers it.
+
+Nothing here has to be understood or operated yet.
+Looking is enough.
+
+
+
+
+
+## Graph Insights
+
+
+
+Graph Insights shows a knowledge graph as a readable picture: similar things are grouped, and the connections between the groups are summarized.
+Each step offers only the relationships the data actually uses, so no path leads to an empty view.
+Filters narrow what is shown, and no query is needed.
+
+{ class="bordered" width="60%" }
+
+[:octicons-arrow-right-24: Graph Insights](../../explore-and-author/graph-exploration/graph-insights/index.md)
+
+## Business Knowledge Editor
+
+
+
+The Business Knowledge Editor is where an individual thing in a knowledge graph is read and changed.
+It appears as a diagram with its relationships, labeled with the names the business uses.
+Both can be added to or edited.
+Any changes become part of the graph, so everything built on it sees them.
+
+{ class="bordered" width="60%" }
+
+[:octicons-arrow-right-24: Business Knowledge Editor](../../explore-and-author/bke-module/index.md)
+
+## Shape views
+
+Shape views present graph data in whatever form a task needs: a form with business field labels, a map, a diagram.
+The presentation follows the model rather than code, so a change to the model changes every view built on it.
+
+{ class="bordered" width="60%" }
+
+[:octicons-arrow-right-24: Building a customized user interface](../../explore-and-author/graph-exploration/building-a-customized-user-interface/index.md)
+
+## Mapping Creator
+
+The Mapping Creator connects the columns of a source to the things and relationships of the knowledge graph.
+The mapping is drawn as lines between source and target, by hand or proposed by artificial intelligence (AI).
+Each suggestion is accepted or rejected by a person, individually or in bulk.
+The tedious half of the work is proposed, while the decision about what the data means stays with a person.
+
+{ class="bordered" width="60%" }
+
+[:octicons-arrow-right-24: Mapping Creator](../../build/mapping-creator/index.md)
+
+## Companion
+
+Companion is an AI agent built into Corporate Memory.
+A question about the data, asked in plain language, is answered from the knowledge graph.
+That opens the graph to people who never write a query.
+Intentions for a data pipeline, described in plain language, are translated into Build workflows, transformations and other tasks.
+
+{ class="bordered" width="40%" }
+
+[:octicons-arrow-right-24: Companion AI Chat](../../explore-and-author/companion/index.md)
+
+## Next
+
+- Basic, the hands-on path to a first knowledge graph in about four hours, is in preparation.
+ Until then, the [Tutorials](../../tutorials/index.md) cover the first steps.
+
+
+
+## Browse all documentation
+
+The complete documentation is organized by module:
+[Build](../../build/index.md) ·
+[Explore](../../explore-and-author/index.md) ·
+[Consume](../../consume/index.md) ·
+[Distribution](../../distribution/index.md) ·
+[Deploy and Configure](../../deploy-and-configure/index.md) ·
+[Automate](../../automate/index.md) ·
+[Develop](../../develop/index.md) ·
+[Release Notes](../../release-notes/2026/corporate-memory-26-2/index.md) ·
+[Tutorials](../../tutorials/index.md)
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+---
+title: "Introduction: Semantic Web basics"
+tags:
+ - KnowledgeGraph
+ - Vocabulary
+---
+
+# Semantic Web basics
+
+This is a compact overview of the terms that the rest of this documentation assumes.
+Those terms are triple, Internationalized Resource Identifier (IRI), literal, prefix, class, property, vocabulary and graph.
+Each term is shown as it appears in eccenca Corporate Memory.
+
+The overview is optional and takes about 35 minutes.
+It is a bridge, not a course.
+It covers enough to read the documentation and to work with the product, and points to a full course for everything beyond that.
+
+Skip ahead when triple, IRI and vocabulary are familiar terms.
+Nothing here is specific to Corporate Memory that does not also appear later.
+Read on when Resource Description Framework (RDF) and ontology are words heard but never used.
+Either way, the introduction continues with [eccenca Corporate Memory at a glance](../corporate-memory-at-a-glance/index.md).
+
+## Why the meaning has to be written down
+
+Software reads text without understanding it.
+
+"The fisherman went to the bank" is clear to a reader and ambiguous to a machine, which cannot tell a riverbank from a financial institution.
+A person resolves this from context.
+Software has no context unless the context is recorded.
+
+The same applies to structure.
+A column headed `loc` is meaningful to the team that created it and opaque to everyone else, including every program that reads the table later.
+
+The terms are the agreed way of recording what something is and how it relates to other things.
+Their purpose is that the meaning travels with the data instead of living in someone's head.
+
+[What is a knowledge graph?](../what-is-a-knowledge-graph/index.md) explains why a graph is the shape that makes this possible.
+
+## The terms
+
+### Triple
+
+A triple is the smallest complete statement: subject, predicate, object.
+`Product 10045` — is made at — `Plant Leipzig` is one triple.
+A knowledge graph is a large collection of triples.
+
+{ class="bordered" }
+
+In the product: open a resource in Explore and select the **Properties** tab.
+The resource is the subject, and each row is one predicate with its object.
+
+{ class="bordered" width="70%" }
+
+### IRI
+
+An IRI identifies a thing, globally and uniquely, and is written like a web address: `https://example.org/product/10045`.
+IRI is the internationalized form of Uniform Resource Identifier (URI).
+
+A plain number does not work for this purpose.
+The number `10045` means something different in each source system, while an IRI cannot collide with another system's identifier.
+
+In the product: **Copy resource identifier** in the :eccenca-item-moremenu: menu of a resource copies its IRI.
+
+{ class="bordered" width="40%" }
+
+### Literal, datatype and language tag
+
+A literal is a value rather than a thing: a number, a date, a piece of text.
+IRIs name the things, literals hold what is known about them.
+
+By default a literal is text.
+`"12.3833"` looks like a number but sorts like text, which puts `"02"` before `"100"` before `"11"`.
+A datatype fixes this: `"12.3833"^^xsd:decimal` is a number and sorts like one.
+
+A text literal can also carry a language tag, so one thing can have a label in several languages at once: `"Leipzig"@de` and `"Lipsia"@it`.
+
+In the product: the **Properties** tab distinguishes the two.
+A value shown as plain text, such as `58` for **height (mm)**, is a literal.
+A value shown as a chip, such as **White-Nash (Pakistan)** for **supplier**, is a link to another thing.
+
+### Prefix
+
+A prefix is a shorthand for the long part of an IRI.
+Declaring `ex:` for `https://example.org/` shortens the identifier above to `ex:product/10045`.
+
+In the product: prefixes are managed per project and are chosen while a mapping is built, which makes them worth choosing deliberately.
+
+### Class and property
+
+A class is a kind of thing, such as a product, a plant or a supplier.
+A property is a kind of statement that can be made about a thing, such as is made at or has article number.
+
+Classes and properties are themselves things with IRIs.
+This is what makes a graph self-describing: the description of the data lives in the same graph as the data.
+
+In the product: the class tree in Explore lists the classes, and the rows of a resource view are its properties.
+
+### Vocabulary and ontology
+
+A vocabulary is the agreed set of classes and properties for a domain.
+It is the shared answer to what things are called and which statements may be made about them.
+Vocabularies exist for many common domains, and reusing one is usually better than inventing another.
+
+In practice the two words are used interchangeably.
+Where a distinction is made, ontology implies formal rules about what follows from what.
+
+In the product: the Vocabulary Catalog holds the vocabularies, and a target vocabulary is selected when a mapping is started.
+
+### Graph
+
+A graph is a named container for triples.
+Data does not land in one undifferentiated heap.
+It goes into a named graph, so that it can be replaced, versioned or kept apart from other data.
+
+In the product: the target graph is selected when a workflow is set up.
+
+## What this looks like written down
+
+A graph has to be written to a file in order to be exchanged, and the common format for that is Turtle.
+
+```turtle
+@prefix ex: .
+@prefix rdfs: .
+@prefix xsd: .
+
+ex:product10045
+ a ex:Product ;
+ rdfs:label "Product 10045"@en ;
+ ex:articleNumber "10045" ;
+ ex:weight "4.2"^^xsd:decimal ;
+ ex:madeAt ex:plantLeipzig .
+```
+
+Every term above appears in those few lines.
+There are three prefixes and their IRIs, a class after `a`, four properties, and literals with a language tag and a datatype.
+The keyword `a` states the class of the subject, and is the Turtle shorthand for the property `rdf:type`.
+The semicolons group statements that share a subject.
+
+Writing Turtle by hand is not required in order to work with Corporate Memory.
+Recognizing it is useful, because an exported graph looks like this.
+
+## What is left out
+
+Three subjects are named in the documentation and deliberately left out here:
+
+- SPARQL is the query language for graphs.
+ Much of Explore works without writing any, and the [Queries](../../explore-and-author/query-module/index.md) documentation covers it where it is needed.
+- Shapes Constraint Language (SHACL) records what must be true about the data.
+ It is used both for validation and for shaping the forms that people see.
+- Modeling techniques such as blank nodes and relations between more than two things belong next to the task that needs them, in the [Build](../../build/index.md) documentation.
+
+## Going deeper
+
+The recommended course is [Knowledge Graphs – Foundations and Applications](https://open.hpi.de/courses/knowledgegraphs2023) by Prof. Dr. Harald Sack of FIZ Karlsruhe and Karlsruhe Institute of Technology, hosted on openHPI.
+The course consists of six weeks of material and a final exam.
+It is held in English, is free of charge, and is available in self-study mode at any time.
+
+Self-study mode leads to a Confirmation of Participation.
+Graded certificates require a live course run, so the course page is the place to check for the next one.
+
+The group behind the course publishes further material openly at Information Service Engineering, FIZ Karlsruhe.
+
+
+This documentation links to these resources rather than reproducing them.
+They are maintained by the people who teach them.
+
+## Next
+
+- [eccenca Corporate Memory at a glance](../corporate-memory-at-a-glance/index.md): the parts of the product and how they relate
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+
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+
diff --git a/docs/introduction/what-is-a-knowledge-graph/index.md b/docs/introduction/what-is-a-knowledge-graph/index.md
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+---
+title: "Introduction: What is a knowledge graph?"
+tags:
+ - KnowledgeGraph
+---
+
+# What is a knowledge graph?
+
+A knowledge graph records things and the named relationships between them, in a form that both people and software can follow.
+
+The documentation uses the term throughout, because it is what eccenca Corporate Memory builds and works with.
+The terms that come with it, such as triple, Internationalized Resource Identifier (IRI) and vocabulary, are covered in [Semantic Web basics](../semantic-web-basics/index.md), which is optional.
+
+## Things and relationships
+
+Most business data lives in tables.
+A table is a good answer to a question that was known in advance.
+Its columns are fixed, and every row answers the same question in the same shape.
+
+The questions that cause trouble are the ones nobody planned for.
+Which products are affected if a supplier fails?
+The answer usually exists, spread over several systems, each with its own name for the same product.
+Producing it means a join that somebody writes and somebody else maintains.
+
+A knowledge graph turns that around.
+Instead of rows in fixed columns, it records the things themselves and how they are connected:
+
+- Product 10045: is made at Plant Leipzig
+- Plant Leipzig: is supplied by Kessler GmbH
+
+{ class="bordered" }
+
+Each connection carries a name.
+"Is made at" is not a column heading that a reader has to interpret, and not a foreign key that only the application understands.
+It is a statement, written down, that software can follow as reliably as a person can read it.
+
+## What that changes
+
+Three things follow, and they are the reason the term appears in this documentation at all.
+
+New questions need no new structure.
+Anything connected can be followed, in any direction, without that path having been planned.
+The question about the failed supplier is answered by walking from the supplier to the plants to the products.
+Nobody has to have anticipated it.
+
+{ class="bordered" }
+
+A new source connects instead of becoming another island.
+A fourth system attaches to things that already exist.
+It does not arrive as another table that nobody has joined yet.
+
+The meaning travels with the data.
+A graph records not only that two things are related but what the relation means.
+That is what allows a result to be explained, checked and reused, rather than only produced.
+
+## Identifiers do not disappear
+
+A common worry is that connecting systems means overwriting what they contain.
+
+The opposite happens.
+The same product may be `P-10045` in one system, `PRD_10045_A` in a second and `45100-XX` in a third.
+In a knowledge graph these become properties of one product.
+Each fact can be traced back to the system it came from, and written back to it where that makes sense.
+
+{ class="bordered" }
+
+## What a knowledge graph is not
+
+Not a replacement for existing systems.
+The source systems keep running and keep their data.
+A graph adds the layer where their contents are related to one another.
+
+Not a data warehouse or a reporting tool.
+A warehouse is built to aggregate numbers for known reports.
+A graph is built to represent meaning and to answer questions that were not foreseen.
+
+Not automatic.
+The relationships have to be stated deliberately.
+That work is what the [Build](../../build/index.md) part of Corporate Memory is for, and it is the reason the result can be trusted later.
+
+## Where the terminology comes from
+
+Knowledge graphs are built on a set of open standards, usually grouped under the term Semantic Web.
+Those standards are why words such as triple, IRI and vocabulary appear in this documentation.
+
+None of them are needed here.
+The optional [Semantic Web basics](../semantic-web-basics/index.md) introduce them and show what each one looks like in Corporate Memory.
+
+## Next
+
+- [Semantic Web basics](../semantic-web-basics/index.md): optional, the terminology, about 35 minutes
+- [eccenca Corporate Memory at a glance](../corporate-memory-at-a-glance/index.md): the parts of the product and how they relate
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+
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+
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diff --git a/nav.yml b/nav.yml
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--- a/nav.yml
+++ b/nav.yml
@@ -3,6 +3,18 @@
# Do not edit by hand - run `task update:navigation` instead.
# yamllint disable rule:line-length
nav:
+ - Home:
+ - index.md
+ - What is a knowledge graph?:
+ - introduction/what-is-a-knowledge-graph/index.md
+ - Semantic Web basics:
+ - introduction/semantic-web-basics/index.md
+ - At a glance:
+ - introduction/corporate-memory-at-a-glance/index.md
+ - Get access:
+ - introduction/get-access/index.md
+ - See it in the product:
+ - introduction/see-it-in-the-product/index.md
- Build:
- Build: build/index.md
- Introduction to the User Interface: