Show difference between two commits or branches

To view difference between two branches:

git diff <branch1>..<branch2>

To view difference between two commits:

git diff <commitId1>..<commitId2>

To view diff against current branch:

git diff <branch/commitId>

To view summary of changes:

git diff --stat <branch/commitId>

To view files that changed after a certain commit:

git diff --name-only <commitId>

To view files that are different than a branch:

git diff --name-only <branchName>

To view files that changed in a folder after a certain commit:

git diff --name-only <commitId> <folder_path>