Blast can also be used to align two sequences, but is most commonly used to compare a sequence against all entries in a database of sequences.
The NCBI BLAST website has a few variants that people can use:
- Nucleotide BLAST (blastn): search for similar nucleotide sequences in a nucleotide sequence database
- blastx: search protein databases using a translated nucleotide query
- tblastn: search translated nucleotide databases using a protein query
- Protein BLAST (blastp): search for similar protein sequences in a protein sequence database
Or, how NCBI visualizes it themselves:
