Git history and logs

Git keeps a full history of every commit. git log shows what changed, who changed it, and when, which is useful for finding when a bug was introduced.

git log                    # full history
git log --oneline          # one line per commit
git log --oneline --graph  # show branches visually
git log -p app/page.tsx    # changes to one file
git show 3f2ef2e           # details of one commit
git diff                   # unstaged changes
git blame app/page.tsx     # who last changed each line