The positional difference for each word between the two sequences is obtained by ________ the position of the ______ sequence from that of the _______ sequence and is expressed as the offset.

Database similarity search is based upon sequence alignment methods also used in pairwise sequence comparison. Sequence alignment can be global (whole sequence alignment) or local (partial sequence alignment) and there are algorithms to find the optimal alignment given particular comparison criteria.

Topics include: Heuristic Database Searching, FASTA, Comparison of FASTA and BLAST, & Database Searching with the Smith – Waterman Method.