Version Control System (VCS), also known as source control, is a system that records changes to sets of files, and maintains a history of all the past file versions. A VCS can be used for any type of files, but it is commonly used to track changes in software development projects.
By this point in the book, you may have already checked your project into source control. In fact, you may have done so as soon as you had a working version of your very first function. Being accustomed to using source control creates an automatic desire to commit any meaningful changes, and for a good reason. Using a VCS may seem so obvious that I have questioned whether this book should even cover the source control benefits. There are, however, some scary survey statistics out there claiming that less than 50% of all software projects are in any type of VCS.
I prefer not to make authoritative statements about software development, but I will make this one:
If you are not using source control...