This quick overview will cover how to compare changes between commits or any commit in git log history.
Compare from the last commit:
git diff HEAD^ HEAD
Or alternatively, use commit IDs
git diff 0594b24 3851af3
Or using alias
git diff @^ @
Comparison by default compares to the HEAD you can further rewrite to
git diff HEAD^
git diff 0594b24
git diff @^
or simply use which compares to the last commit.