To see a list of which commits are on one branch but not another, use git log:
git log --no-merges oldbranch ^newbranch
…that is, show commit logs for all commits on oldbranch that are not on newbranch. You can list multiple branches to include and exclude, e.g.
git log --no-merges oldbranch1 oldbranch2 ^newbranch1 ^newbranch2
Note: on Windows command prompt (not Powershell) ^
is an escape key, so it needs to be escaped with another ^
:
git log --no-merges oldbranch ^^newbranch