Pairwise alignment (Proteins only)
This calculation is performed on the selected sequences only. Java is not the
  fastest language in the world and aligning more than a handful of sequences
  will take a fair amount of time. 
  For each pair of sequences the best global alignment is found using BLOSUM62
  as the scoring matrix. The scores reported are the raw scores. The sequences
  are aligned using a dynamic programming technique and using the following gap
  penalties : 
Gap open : 12 
  Gap extend : 2 
When you select the pairwise alignment option a new window will come up which will display the alignments in a text format as they are calculated. Also displayed is information about the alignment such as alignment score, length and percentage identity between the sequences.