Say I have 2 commits which I have already pushed to my remote branch.
How do I revert to Commit B without deleting Commit A? I just want to compare the result between these 2 commits.
Note: Code comparison is not needed. I just want to compare the output of Commit A vs Commit B
I strongly disagree with the other answers advising you to use git revert. This would actually really revert the changes introduced by Commit A and produce a commit on its own.
Since you want to have a look at the state at a point back in time, you could just checkout Commit B directly so you can inspect the contents. Afterwards checkout the original branch to go back to the latest commit.
git checkout $HASH_OF_COMMIT_B # now you are in a detached head state at commit B
git checkout $BRANCH # now you are back at the tip of the branch (commit A)
A lot of tools let you see the difference between two references directly without the need to checkout. On the command line, this could be done with git diff:
git diff $HASH_OF_COMMIT_A..$HASH_OF_COMMIT_B