Repositories, working trees, and the object database

What you will learn

• Explain repositories in Git using the correct mental model
• Trace a focused Git example and predict its result before execution
• Recognize a boundary case involving working trees and handle it deliberately

The concept

Repositories, working trees, and the object database is a defining part of practical Git work. Start by identifying the data or state involved, then trace the operation that changes or interprets it. Pay attention to the rules Git applies at this boundary, because those rules explain both the useful behavior and the common failure modes. This lesson keeps the example deliberately small, then connects it to status, diffs, staging, and commits so the ideas form a coherent progression rather than a list of isolated syntax facts.

Example

This example is intentionally small so you can trace every line before adapting it.

git init
git add .
git commit -m "Start a small project"

Read it step by step

1. 1
   Locate the idea

   Identify where repositories appears in the Git example and name the data it operates on.

2. 2
   Trace the rule

   Trace the relevant Git rule one operation at a time, recording any state, type, or control-flow change.

3. 3
   Test a boundary

   Change one input or boundary condition, predict the result, and compare that prediction with the documented outcome.

Common mistakes

Try it yourself