How can we diverge two branches in Git?

A branch in git is a series of interrelated commits. If two branches follow a non-linear path then they diverge each other. The diagram shows two diverged branches master and feature.

Consider the above diagram. Let us assume that both the branches were following a linear path before the initial commit. After the initial commit, the branch master has an independent commit c1 and the branch feature has its own commit c2. As the branches now follow a non-linear path, we can say that both the branches are diverged. Let us see this through an example

Step 1 − Create an empty repository with an initial commit.

$git init
$echo hello>hello.txt
$git add .
$git commit -m 'Initial commit'

Output

[master (root-commit) dC3b134] Initial commit
1 file changed, 1 insertion(+)
create mode 100644 hello.txt

Step 2 − Create a new branch named feature

$git branch feature
$git branch

Output

Below output shows that the repository has two branches available, with master being the current branch (*)

Feature
* master

Step 3 − Create a new commit in the master branch and check the history

$echo world>world.txt
$git add .
$git commit -m ‘world.txt’
$git log --oneline --all --graph

Output

Below output shows that the feature branch is pointing to the initial commit whereas the master branch has an independent commit.

* d6e2f5b (HEAD -> master) world.txt
* dC3b134 (feature) Initial commit

Step 4 − Switch to the feature branch and create a new commit

$git switch feature
$echo file1>file1.txt
$git add .
$git commit -m ‘file1.txt’
$ git log --oneline --all --graph

Output

The output displays the history graph of commits.

* e340791 (HEAD -> feature) file1.txt
| * d6e2f5b (master) world.txt
|/
* dC3b134 Initial commit

The initial commit hash dC3b134 was common to both the branches whereas the commit e340791 and d6e2f5b is specific to the feature and the master branch respectively. This proves that the branches are diverged from each other.