What a branch is (pointer to a commit) in Git - Step-by-Step Execution

Process Flow - What a branch is (pointer to a commit)

Start: Commit A

↓

Commit B

↓

Commit C

↓

Commit D

A branch is like a label that points to a specific commit in the project history. When you add new commits, the branch pointer moves forward to the latest commit.

Execution Sample

Git

git init
# Create initial commit A
# Commit B added
# Commit C added
# Create branch 'feature' at commit C
# Commit D added on 'feature' branch

Shows how branches point to commits and move as new commits are added.

Process Table

Step	Action	Branch Pointer	Commit History	Notes
1	Initialize repo and create commit A	main -> A	A	Initial commit, main points to A
2	Add commit B on main	main -> B	A -> B	main moves to B
3	Add commit C on main	main -> C	A -> B -> C	main moves to C
4	Create branch 'feature' at commit C	main -> C, feature -> C	A -> B -> C	feature points to same commit as main
5	Add commit D on feature branch	main -> C, feature -> D	A -> B -> C -> D	feature moves to D, main stays at C

💡 Execution stops after commit D; branches point to their latest commits.

Status Tracker

Branch	Start	After Step 2	After Step 3	After Step 4	After Step 5
main	A	B	C	C	C
feature	-	-	-	C	D

Key Moments - 2 Insights

Why does the 'main' branch pointer not move when a commit is added to 'feature'?

Because branches are independent pointers. When commit D is added on 'feature', only 'feature' moves forward. 'main' stays at commit C as shown in step 5 of the execution_table.

What happens when a new branch is created at a commit?

The new branch pointer points exactly to that commit, sharing history up to that point. See step 4 where 'feature' points to commit C, same as 'main'.

Visual Quiz - 3 Questions

Look at the execution table at step 3, where does the 'main' branch point?

A Commit B

B Commit A

C Commit C

D Commit D

💡 Hint

Check the 'Branch Pointer' column at step 3 in the execution_table.

At which step does the 'feature' branch get created?

A Step 2

B Step 4

C Step 3

D Step 5

💡 Hint

Look for when 'feature' first appears in the 'Branch Pointer' column.

If a new commit is added to 'main' after step 5, what happens to the 'feature' branch pointer?

A It stays at commit D

B It moves forward to the new commit

C It moves back to commit C

D It is deleted

💡 Hint

Branches move independently; see how 'main' and 'feature' pointers differ in the execution_table.

Concept Snapshot

A branch in git is a pointer to a commit.
It moves forward as new commits are added on that branch.
Branches can share history by pointing to the same commit.
Creating a branch copies the pointer to a commit.
Branches move independently when new commits are made.

Full Transcript

In git, a branch is like a label that points to a specific commit. When you create a new commit on a branch, the branch pointer moves forward to that new commit. Multiple branches can point to the same commit, sharing history. When you create a new branch, it points to the current commit you are on. Branches move independently, so adding commits on one branch does not move other branches. This helps manage different lines of work in a project.