How to use version control (and why)

Version control is a way to develop software in a scalable way. Even if you are the only person working on a project, it enables you to write code with more confidence, as you know you have every change tracked - no more wondering what you did which broke everything, as you can find out easily. You can also tag points in development for retrieval later on - it's a good idea to do this before working on big structural changes which could cause instability while you work on them.

Version control can be also be used in order to share development between groups of people, up to hundreds of developers. It takes care of merging all the changes together (which often worries people new to version control) but it generally works well, and if it finds a confusing case (normally where two developers have changed the same line of code) it asks you to confirm what it's doing.