BED (Browser Extensible Data) format in bioinformatics provides a flexible way to define the data lines of genomic features that are displayed in an genome annotation track. BED lines have 3 required fields (chromosome, start position, end position) and 9 additional optional fields. For other bioinformatics formats, such as FASTA, FASTQ, VCF, GFF, BAM/SAM, etc, use their own separate tags.
