Contig

A portion of an assembled genome. When a genome is sequenced, small regions of the genome are sequence contiguously (between 50-2000nt), which are later assembled into larger contiguous pieces. These, in turn, are physically mapped to the genome so they can be ordered, and the gaps between these sequenced regions are targeted for additional sequences to finish a genome (or chromosome). Here is a primer on genome assembly hosted by the Center for Bioinformatics and Computational Biology at the University of Maryland.