Pull request and merge

A pull request is a proposal to fold one branch's changes into the main version, paired with a review of exactly what changed. Merge is the step that combines the two once the review passes.

A pull request is a proposal to fold one branch's changes into the main version, paired with a review of exactly what changed, and merge is the step that combines them once the review passes. Say you ask an AI assistant to add a password reset feature to a to-do app, and it does the work on a separate branch. Opening a pull request lays the proposed edits next to the main version so you can read each changed file before anything affects what visitors use. You approve, and the merge folds the password reset into main; you have second thoughts, and you close the request, so main stays exactly as it was.

Builder example

When an AI coding assistant writes a feature on its own branch, the pull request is where you catch a confident-but-wrong edit before it reaches your live app. You ask the assistant to open the request and summarize what changed, then you read the proposed difference for a support bot and confirm it only touched the files it should have. Approving and merging is one deliberate step you control, so an unrelated change the assistant slipped in gets stopped at review instead of shipping to users.

Common confusion: A branch is the separate line of work where the changes are made; the pull request is the request to bring that branch into the main version, and the merge is the moment the two combine. Opening a pull request does not change main on its own. Nothing moves into main until the merge runs, so a request you never approve leaves main untouched.