git diff – Compare Changes

git diff command:

• Shows differences between working directory and staging area
• Helps see what is modified but not yet staged

How to Read Diff

• a/ → old version of file
• b/ → new version of file
• --- → old file
• +++ → new file
• Lines prefixed with - → removed
• Lines prefixed with + → added

Example workflow:

nano nav-bar.html    # Edit a file
git add nav-bar.html # Stage the file
git diff --staged    # Check staged changes

Comparing Commits

Command / Option	Purpose / Description
git diff	Show changes in working directory vs staging area
git diff --staged / --cached	Show changes in staging area vs last commit
git diff <file>	Show changes for a specific file
git diff --name-only	Show only filenames that changed
git diff --name-status	Show filenames + status (Added / Modified / Deleted)
git diff --color-words	Show inline word-level differences
git diff --stat	Show summary/statistics (files changed, insertions, deletions)
git diff <commit>	Show changes between working directory and a specific commit
git diff <commit1> <commit2>	Show changes between two commits
git diff <hash1>..<hash2>	Compare changes between two commits (shorthand for above)
git diff <branch1>..<branch2>	Show differences between two branches
git diff <commit> -- <file>	Show changes of a specific file compared to a specific commit
git diff --word-diff	Highlight changes at word level instead of line level
git diff --check	Show whitespace errors in changes

Quick Tips

• --staged = view what is about to be committed
• --stat = quick summary of changes
• <commit> or <branch> = compare historical or branch differences
• Combine options for clarity, e.g., git diff --stat --staged