Pull Request
A pull request (PR) is a formal request to merge a set of code changes from one branch into another, typically accompanied by a diff, description, and a review and discussion process before the merge happens.
Definition
A pull request (PR) is a formal request to merge a set of code changes from one branch into another, typically accompanied by a diff, description, and a review and discussion process before the merge happens.
Overview
Pull requests originated as the collaboration mechanism on GitHub (GitLab uses the equivalent term “merge request”) and have become the standard unit of change in modern software development. A developer creates a branch, commits their changes, and opens a pull request against the main branch; this generates a diff view that reviewers can comment on line by line, request changes to, run automated checks against, and ultimately approve before the change is merged. Beyond the mechanical act of merging code, a pull request functions as the central artifact for code review, documentation of why a change was made, and a trigger point for automated CI/CD pipelines — running tests, linting, security scans, and build checks automatically on every proposed change before a human ever needs to look at it. Most teams configure branch protection rules that require passing checks and a minimum number of approvals before a pull request can be merged, turning the PR into a quality gate rather than just a suggestion. Good pull request hygiene — a clear title and description, a reasonably small and focused diff, and linked context such as an issue number — makes review faster and more effective, since reviewers spend less time reconstructing intent and more time evaluating the actual change. Pull requests also serve as a durable historical record: because each one is tied to a specific set of commits and discussion, they let a team trace exactly why and when a piece of code changed, long after the original author has moved on to other work. It is often mentioned alongside Monorepo in this space.
Key Concepts
- Requests merging changes from one branch into another
- Generates a diff view for line-by-line discussion and review
- Serves as the standard trigger for automated CI/CD checks
- Central artifact for code review and documenting why a change was made
- Often gated by branch protection rules requiring approvals and passing checks
- GitLab's equivalent concept is called a merge request
- Creates a durable, searchable historical record of codebase changes