Who & When - show & blame

git show - inspect one commit

$ git show a1b2c3d        # message + full diff of that commit
$ git show HEAD:app.py    # a file's contents AS OF that commit

git show is how you zoom in on exactly one commit once git log has helped you find it - it prints the full commit message plus the complete diff it introduced, so you can see both what changed and why (from the message) in one place.

git blame - who last touched each line

Scenario: A weird line of config is breaking prod and nobody remembers writing it. Before you git blame a person, you git blame the file - it annotates every single line with the commit, author, and date that most recently changed it. Then you read that commit's message (with git show) to learn the why behind the change.

$ git blame config.txt
a1b2c3d (Alice 2024-03-01 14:22) port=8080
9f8e7d6 (Bob   2024-03-05 09:10) timeout=30

Command	Does
`git blame <file>`	Annotate every line with its last commit/author
`git blame -L 10,20 <file>`	Only lines 10-20 (much faster on huge files)
`git show <commit>`	View a commit's full message + diff

Tip: The two commands are meant to be used together: git blame points you to a commit hash; git show <hash> then reveals the full context and reasoning behind that specific line. Despite the name, blame is a tool for understanding history, not for pointing fingers at a teammate - in a healthy team, "let me blame this line" just means "let me find out why this is here".