Overview
A commit saves only staged changes. Unstaged edits remain outside the commit.
A vague message weakens the usefulness of the log because the saved state has little explanation.
Checking out a commit is useful for inspection, but detached HEAD is not the same as returning to a normal development branch. Move back to a branch before continuing ordinary branch-based work.
The order of commit IDs affects diff output, so a confusing comparison may simply need the identifiers reversed.