What is the main branch of a project?

The main branch of a project in Git is the primary "anchor" branch of the repository, around which all development is organized. It usually holds the baseline version of the project that the team, CI/CD, and releases rely on. Most often it is called main (historically master).

#How to tell that a branch is "the main one"

This is not a special branch type inside Git; technically it is a regular branch. What makes it "main" is team agreement and repository configuration:

• it is treated as the source of truth (baseline) for the project;
• feature/fix branches most often branch off it;
• verified changes are usually merged into it via merge/rebase;
• access rights, PR/MR rules, and CI checks are often tied to it.

#What it is for

#1) A stable anchor point

The main branch should reflect a state that:

• can be built,
• can be tested,
• can often be deployed.

That is why teams try to keep it in as working a state as possible.

#2) A shared point for integrating changes

Development almost always happens in parallel: one person works on a feature, another on a bugfix, a third on a refactor. The main branch is where changes:

• are brought together,
• go through checks,
• become part of the shared product.

#3) A basis for releases and versioning

In many processes, a release is made "from main":

• tags are set (for example, v1.4.0);
• artifacts are built;
• deployment pipelines are triggered.

#Approaches to the "main" branch

The choice depends on the development process:

#Option A: main = always ready for production

• only what can be shipped lands in main;
• features go through feature/* branches, then a PR/MR, checks, and a merge.

#Option B: main = an integration branch, while production comes from release/* or stable

• main can be "livelier" and change more often;
• production stability is ensured by a separate release branch.

In practice, teams more often lean toward option A, because it is simpler and enforces discipline.

#How it relates to branches, HEAD, and remote repositories

• Locally, you have a main branch.
• Remotely, there is, for example, origin/main.
• When people say "the main branch", they usually mean the default branch on the server (the one that opens first when you enter the repository) and its local counterpart.
• HEAD usually points to the current branch; if you are on main, then HEAD → main.

#What is usually accepted around the main branch (in practice)

• Direct commits to the main branch are often forbidden.
• Changes get there through a PR/MR with:
  • review,
  • automated tests,
  • linters,
  • a build,
  • quality checks.
• Commits are kept meaningful, and the history readable.

#Short definition

The main branch of a project is the branch considered the primary and baseline one, containing the current stable version, and serving as the integration point for all completed changes; it is most often called main (or master).