BAM (Binary Alignment Map)
From Just Solve the File Format Problem
BAM (Binary Alignment Map) is a data format used for mapping sequences of DNA. It is a compressed binary version of the data in the SAM format. It is classified as an alignment format, as is CRAM. This is as opposed to sequence-only, unaligned, formats such as FASTA and FASTQ.
BAM is compressed as a series of compressed blocks, each one a gzip archive. This is known as BGZF compression.
An index of a BAM is stored in a format called BAI, also described in the spec.
