Why are pack files less in size than the objects of the remote repo?

Question

When we clone a remote we get we get instead of object packed files which seems to be some performance optimization to reduce size.
But how is this optimization done? If I understand these are binary files with the same contents as the original objects so how exactly they occupy less space? Is the implementation some standard one?

Answer 1

As I mention in "How does git store files?", Git does use deltas for storage.

The result includes pack files, using a custom implementation of a diff algo for delta computation.