BED - Browser Extensible Data format, is a text-based tab-delimited format representing intervals (chunks) of sequences, widely used in gene annotations. BED format uses 0-based indices.
3 mandatory columns:
- Chromosome
- Start position
- End position
9 optional columns: 4. Name 5. Score 6. Strand 7. Thick start 8. Thick end 9. Item RGB 10. Block count 11. Block size 12. block starts
BED file example from Ensembl
chr7 127471196 127472363 Pos1 0 + 127471196 127472363 255,0,0
chr7 127472363 127473530 Pos2 0 + 127472363 127473530 255,0,0
chr7 127473530 127474697 Pos3 0 + 127473530 127474697 255,0,0