Mastering Git Internals

Today I decided to look past the basic git add and git commit surface commands to understand how Git actually tracks our code changes under the hood. Git isn't just a simple file tracker—it's a content-addressable filesystem.

The Three Core Objects

When you commit a file, Git generates compressed snapshots and saves them inside the hidden .git/objects directory using SHA-1 hashes. There are three essential object types:

1. Blobs: Stored compressed binary data representing raw file contents. A blob doesn't store file names or directory structures—just the file data.
2. Trees: The equivalent of folders. A tree object lists file names, permissions, and links them to their corresponding file blobs or other nested trees.
3. Commits: A tiny text file containing a link to the top-level tree snapshot, author credentials, timestamps, and a pointer to the parent commit hash. မြန်မာလိုရောအဆင်ပြေလား

Simulating Object Generation

I ran some low-level Git plumbing commands in my terminal to see exactly how Git hashes content.

# Hash a piece of text and write it directly into the Git object store
echo "Hello, Git Internals!" | git hash-object -w --stdin