Code Review
A code review is a software engineering methodology where the code written by one (or more) developers is checked for stylistic and/or logical errors by another developer.
Code Reviews are typically done when one developer considers a feature to be done and wants to merge it. They will typically create a pull request, which another developer has to review before it can be merged into the main development branch.
1 Benefits
1.1 Knowledge Sharing / Learning Opportunity
Checking someone else’s code is a great learning opportunity. You can learn new syntax, language and/or framework features or just neat tricks that are possible in the project space. Also, knowledge about the problem gets transferred to another person, which means that at least two people now know the code on a basic level, which makes future maintainence much easier, especially if the original author isn’t available anymore.
1.2 Cleaner Code
Having someone else look over your code is always a good idea for it to be more maintainable. A developer tends to be very familiar with their own code that they just wrote, which means they will consider objectively unreadable things as readable (since they spent so much time with it).
Code reviews can also prevent errors that just slipped past the attention of the author, or TODO comments that haven’t yet been delt with.