# Git History

**Commit history** is the record of all changes to your project. Use `git log` to view it, `git show` or `git diff` to see what changed, and `git blame` to find who changed each line and why. Understanding history helps you debug problems, understand design decisions, and audit who made what changes.

The simplest way to explore is `git log --oneline` to see a compact list of recent commits, each with its hash and message. For more details, `git log --stat` shows which files changed in each commit. `git show <hash>` displays the full diff of a specific commit, including its message.

```bash
$ git log                    # view full commit history
$ git log --oneline          # compact view with one line per commit
$ git log --stat             # show file statistics for each commit
$ git log -p                 # show full diff for each commit
$ git show <hash>            # view a specific commit's changes
$ git blame <file>           # show who changed each line
$ git diff <hash1> <hash2>   # compare two commits
```

`git blame` is particularly useful when you find a suspicious change—it shows the commit hash, author, date, and the line in question. Use `git log -p <file>` to see the history of changes to a single file, which often makes it easier to understand why something was done.