DevOps · Infrastructure as Code (IaC) · Git Series – Part 4
Git files are the building blocks of version control. Understanding how Git classifies and tracks different file states is essential for effective repository management.

Understanding how Git classifies files is one of the most important skills for any DevOps engineer or developer. Git treats files differently based on whether they are new, changed, staged, or intentionally ignored.

In this chapter, you’ll learn:

• What Git means by tracked, untracked, and modified
• How files move through the Git lifecycle
• How .gitignore works and how to use it
• Real examples & best practices
• Tips to avoid common mistakes

1. Git File Lifecycle Overview

Every file inside a Git repository falls into one of these categories:

1. Untracked

Files Git does not know about yet.
Example: A new file created after git init.

Tracked Git Files

Files Git is watching. These could be:

• Unmodified
• Modified
• Staged

3. Staged

Files you have marked ready for the next commit using git add.

4. Committed

Files stored in Git history.

Below is the official Git file state flow:

Untracked → Staged → Committed → Modified → Staged → Committed → …

Untracked → Staged → Committed → Modified → Staged → Committed → …

2. Checking the Current Status

Use this frequently:

git status

git status

It will show:

• Untracked files
• Modified files
• Staged files
• Ignored files (if you request it)

Untracked Git Files Explained

These are files Git has never seen.

Example:

echo "Notes" > notes.txt
git status

echo "Notes" > notes.txt
git status

You will see:

Untracked files:
  notes.txt

Untracked files:
  notes.txt

✔ To start tracking:

git add notes.txt

git add notes.txt

✔ To track everything:

git add .

git add .

4. Tracked Files

Once Git knows about a file, it becomes tracked.

Tracked files can be:

Unmodified

No change since last commit.

Modified

Content changed, but not staged.

Staged

Changes have been added to the staging area using git add.

Example:

echo "More text" >> notes.txt
git status

echo "More text" >> notes.txt
git status

You will see:

Changes not staged for commit:
  modified: notes.txt

Changes not staged for commit:
  modified: notes.txt

Stage it:

git add notes.txt

git add notes.txt

5. Staged Files

Staged files are prepared for committing.

Example:

git add myfile.txt

git add myfile.txt

This moves it from “modified” → “staged”.

Now commit:

git commit -m "Updated myfile"

git commit -m "Updated myfile"

6. Ignored Files – Using .gitignore

Some files should never be tracked:

• Log files
• Temporary files
• Build output
• Secrets
• Cache folders
• OS-generated files

This is where .gitignore comes in.

7. Creating a .gitignore File

Create a file named:

.gitignore

.gitignore

Add patterns of files you want Git to ignore.

Example .gitignore:

# OS files
Thumbs.db
.DS_Store
# Logs
*.log
# Dependencies
node_modules/
# Python cache
__pycache__/
# IDE settings
.vscode/
.idea/
# Environment secrets
.env

# OS files
Thumbs.db
.DS_Store

# Logs
*.log

# Dependencies
node_modules/

# Python cache
__pycache__/

# IDE settings
.vscode/
.idea/

# Environment secrets
.env

Apply it:

git status

git status

Git will now hide these from the untracked list.

8. Important: .gitignore Only Works for Untracked Files

If a file is already tracked, ignoring it won’t remove it.

Example:

.env file committed accidentally

.env file committed accidentally

Then you add .env inside .gitignore.

Git will still track it.

To stop tracking:

git rm --cached .env

git rm --cached .env

9. View Ignored Files

git status --ignored

git status --ignored

10. Realistic Hands-On Example

mkdir git-files-demo
cd git-files-demo
git init

mkdir git-files-demo
cd git-files-demo
git init

Create files:

echo "Hello" > app.txt
echo "Secret key" > secrets.env
echo "Debug info" > debug.log

echo "Hello" > app.txt
echo "Secret key" > secrets.env
echo "Debug info" > debug.log

Check status:

git status

git status

Add .gitignore:

*.log
*.env

*.log
*.env

Now status shows:

Untracked files:
  app.txt
Ignored files:
  debug.log
  secrets.env

Untracked files:
  app.txt
Ignored files:
  debug.log
  secrets.env

Track only app.txt:

git add app.txt
git commit -m "Added app file"

git add app.txt
git commit -m "Added app file"

11. Best Practices for Git File Handling

✔ Always create .gitignore early

Avoid committing secrets or junk files.

✔ Don’t commit:

• .env
• Credentials
• Cache
• Build artifacts
• OS files

✔ Review git status before each commit

Avoid accidental commits.

✔ Use global .gitignore for OS noise

For example:

git config --global core.excludesfile ~/.gitignore_global

git config --global core.excludesfile ~/.gitignore_global

Add:

.DS_Store
Thumbs.db
*.swp

.DS_Store
Thumbs.db
*.swp

12. What’s Next?

Now you understand:

✔ Tracked vs untracked
✔ Modified vs staged
✔ How .gitignore works
✔ How files move in Git
✔ How to avoid accidental commits

Next up:

➡️ Part 5 – Git Staging: Understanding the Staging Area & How It Works
You’ll learn how the staging area acts as Git’s “preview zone,” how partial staging works, and how to manage changes like a pro.

For more information about Git best practices, refer to the official Git documentationGit Get Started – Creating Your First Repository & Making Your First Commit and our comprehensive guide on repository initialization.