A Peer Review is where you get a group of people and have them look over what you built to make sure it makes sense. You could get any group of people to do this review for you, the only requirement is that they have a strong background in the tools you employed to build your project. These people can be coworkers, peers, even people you don’t know. You are getting a fresh perspective, someone who doesn’t make the same decisions as you, and having them arrive at the same logical conclusions you did without skepticism.