A contiguous segment of the genome made by joining overlapping clones or sequences. A clone contig consists of a group of cloned (copied) pieces of DNA representing overlapping regions of a particular chromosome. A sequence contig is an extended sequence created by merging primary sequences that overlap. A contig map shows the regions of a chromosome where contiguous DNA segments overlap. Contig maps provide the ability to study a complete and often large segment of the genome by examining a series of overlapping clones, which then provide an unbroken succession of information about that region.