e.g., you’re building an app from source and you were at commit fc8c4883. You just pulled the latest changes and you want to know what’s changed since your last update:
git log --graph --decorate --pretty=oneline --abbrev-commit fc8c4883~1..HEAD
There you go, your nice, neat change list comprising commit messages awaits :)
(The key bit is the X~1..HEAD, everything else is just formatting.)