What are pull requests and code review?

Question

Accepted Answer

A **pull request** (PR) — or merge request — is a request to merge changes from one branch into another, providing a place for **code review**, discussion, and automated checks before integration. PRs are central to modern collaborative development and code quality.

## What a pull request is

```text
A PR proposes merging a branch (e.g. a feature) into another (e.g. main):
  → shows the DIFF (what changed), a description, and discussion
  → reviewers comment, request changes, or approve
  → CI runs automated checks (tests, linting, builds) on the PR
  → once approved + checks pass → MERGE into the target branch
→ It's a gate and collaboration point before code is integrated.
```

## The PR workflow

```text
1. Create a feature branch; make commits; push it
2. Open a PR (feature → main) with a clear description of what/why
3. Automated CHECKS run (tests, lint, build) — must pass
4. REVIEWERS examine the code: comment, suggest, approve, or request changes
5. Author addresses feedback (more commits)
6. Approved + checks green → MERGE (merge commit, squash, or rebase)
```

## Why code review matters

```text
✓ QUALITY — catches bugs, design issues, and edge cases before they reach main
✓ KNOWLEDGE SHARING — others learn the code; the author gets feedback; spreads context
✓ CONSISTENCY — enforces standards, conventions, best practices
✓ SHARED OWNERSHIP — more than one person understands each change
✓ MENTORSHIP — a venue for learning and improving
```

## Good PR practices

```text
✓ Keep PRs SMALL and focused (easier, better reviews — huge PRs get rubber-stamped)
✓ Clear title and description (what, why, how to test)
✓ Respond constructively to feedback; review others' PRs thoughtfully and kindly
✓ Ensure CI passes before requesting review
```

## Why it matters

Understanding pull requests and code review is important because they're **central to modern collaborative development and code quality**, so it's valuable practical knowledge for professional team work.

A **pull request** is the standard mechanism for proposing and integrating changes — providing a place to see the diff, discuss, run automated checks, and review code before it's merged, serving as a quality gate and collaboration point.

Understanding the **PR workflow** (creating a feature branch, opening a PR with a clear description, automated CI checks running, reviewers examining and giving feedback, the author addressing it, and merging once approved and green) is essential because this workflow is how the vast majority of professional teams integrate code — a near-universal process.

Critically, understanding **why code review matters** is valuable: it improves **quality** (catching bugs, design issues, and edge cases before they reach main), enables **knowledge sharing** (others learn the code, context spreads, the author gets feedback), enforces **consistency** (standards and conventions), creates **shared ownership**, and provides **mentorship** — making code review one of the most valuable practices for both code quality and team health.

Understanding **good PR practices** (keeping PRs small and focused for effective review, since huge PRs get rubber-stamped; clear descriptions; constructive feedback) reflects professional collaboration skills.

Since pull requests and code review are central to how modern teams develop software (the standard for integrating changes with quality control and collaboration), and since understanding the workflow, the value of review, and good practices is essential for effective professional team work, understanding pull requests and code review is valuable, frequently-relevant knowledge for collaborative development — a core part of professional software practice that directly affects code quality, knowledge sharing, and team effectiveness, and a near-universal aspect of working on software teams.