Off topic:Galaxy's Stitch MAF Blocks

Question

[Kasthuri]

This is about the module "Stitch MAF blocks" which can be found in "Fetch Alignments" in Galaxy.

Can somebody explain how Galaxy "stitches" different sequences from different species based on a given sequence in a species? How does it know the coordinates in other species or does it simply blasts the sequence against other genomes?

Thanks