The BIOM file format (canonically pronounced biome) is designed to be a general-use format for representing counts of observations (e.g., OTUs, KO categories, lipid types) in one or more biological samples (e.g., microbiome samples, genomes, metagenomes).
Further details can be found at http://biom-format.org.
To get help with biom, you should use the biom tag on StackOverflow (SO), or post to the QIIME 2 Forum. Before posting a question, check out SO's guide on how to ask a question. The biom-format developers regularly monitor the biom SO tag.