Select the pull request you'd like to review from the list of pull requests.
Click Files modified on the pull request.
Examine the modifications in the pull request and, if desired, leave comments on individual lines.
Go to the original GitHub repository and look for the big green button that says "Compare and pull request." When you click that button, you'll be directed to a page where you can describe your pull request and see the changes you've made.
Pull requests allow you to notify others about changes you've made to a branch in a GitHub repository. You can debate and review potential modifications with collaborators and make follow-up commits before your changes are merged into the base branch once a pull request is filed.
Branches allow you to work on new features, address bugs, or test new ideas in a secure portion of your repository. A branch is always created from an existing branch. Typically, you would build a new branch from your repository's default branch.
A branch is nothing more than a different version of the code. A pull request occurs when someone takes the repository, creates their own branch, makes modifications, and then attempts to merge that branch into the other person's code repository.