How can I inspect exactly what changed in a particular Git commit?

Run git show <commit>, replacing <commit> with the identifier you want to inspect. For example:

git show abc1234

Git displays that commit’s log message and textual diff. The diff shows recorded changes, rather than simply showing the current contents of files in your working tree. [S1]

For a compact file-level overview, use:

git show --stat --name-status abc1234

This summarizes changed paths and their status. Use git show abc1234 when you want to read the textual changes themselves. [S1] These commands display information; they do not modify the working tree.

No. The file list is a summary; the textual diff from git show <commit> lets you inspect the changes recorded in that commit. It is not necessarily the same as the files’ current contents. [S1]

For example, to inspect the recorded changes to notes.txt in commit abc1234, run git show abc1234 and look for that file’s section in the diff. The diff shows the changes, but it is not necessarily a complete copy of either version of the file.

If you instead want to see how your working tree differs from that commit, run git diff abc1234. That one-commit form compares the working tree with the specified commit. [S2] Choose git show for the commit’s recorded changes and git diff for the working-tree comparison.

Name both endpoints:

git diff abc1234 def5678

This compares the two specified commits. It does not list every commit between them; git diff compares the endpoints you supply. [S2]

For a single commit’s message and patch, use git show <commit>. One case to keep in mind is a merge commit: by default, git show displays it in a combined-diff format, whose interpretation may differ from an ordinary single-parent commit. [S1] If the output looks unfamiliar, check whether you are inspecting a merge commit before interpreting it as an ordinary commit diff.

Use the commands that match your question; you do not need to run all of them:

git show [chosen-commit]
git show --stat --name-status [chosen-commit]
git diff [chosen-commit]
git diff [first-commit] [second-commit]

The first command shows the chosen commit’s message and textual diff; the second summarizes changed paths. The third compares the working tree with the chosen commit, and the fourth compares two commits. [S1] [S2]

To keep a note of your inspection, record something like: “Commit: [chosen-commit]. Comparison: [commit diff / working tree / two commits]. Files of interest: [paths].” That makes clear which view you checked without treating the commit’s recorded changes as a description of the current files.