How exactly Bazaar does handling of binary files?

[Thar]

Hello,

I have a question on the issue presented in the FAQ here:

http://bazaar-vcs.org/FAQ?#head-e6448836a60a73c1954f287ef5e928b79e3ff005

That is - there is something about binary diffs. But can someone make
it clear: is, during the checkout, Bazaar generates diffs between
local and remote files (which is pretty resource-heavy), sends that
limited portion of data and applies it locally, or is it just a
regular sending of the whole file and overwriting the local one?
Finally, FAQ states that "there are tools better suited to that". My
apologies for asking it here on the Bazaar mailing list, but I spent
quite a time looking for one, and found nothing. If anynone knows it,
sharing a name would be very helpful.

I'll appreciate your answer.

Regards