Files and Commits

Creating a New File

Create a file directly in your repository.

1. On the repository page, click Add file → Create new file
2. Enter the file name: notes.md
3. Write the content:

# Study Notes

## What I Learned Today

- Creating a GitHub repository
- Writing a README
- Committing files

## Up Next

- Branches
- Pull Requests

4. In the Commit changes section below:
   • Commit message: docs: add study notes file
   • Select Commit directly to the main branch
5. Click Commit new file

Editing a File

You can also edit existing files.

1. Click the notes.md file
2. Click the pencil icon
3. Make your edits
4. Save with Commit changes

Viewing Commit History

Every change is recorded. Take a look.

1. On the repository main page, click the N commits link (above the file list)
2. Click any commit to see what changed

Green lines (+): Added content
Red lines (-): Removed content

This is called a diff.

"Why?" — Why Good Commit Messages Matter

Commit messages are letters to your future self and your teammates. Six months later, when you search "why did I change this file?", the commit message has the answer.

Bad commit messages:

fix
asdf
update

Good commit messages:

docs: add installation instructions to README
fix: resolve login button click error
feat: add dark mode feature

Tips for writing commit messages:

• Be clear about what you did (save "why" for the body if needed)
• Start with a present-tense verb: "add", "fix", "remove"
• Keep it concise (50 characters or fewer recommended)

Many teams use type prefixes like feat:, fix:, docs: (Conventional Commits). Consistency makes the history much easier to read.

Deep Dive