"Source control is the very bedrock of software development. Without some sort of version control system in place, you can't reasonably call yourself a software engineer. If you're using a source control system of any kind, you're versioning files almost by definition. The concept of versioning is deeply embedded in every source control system. You can't avoid it.
But there's another concept, equally fundamental to source control, which is much less frequently used in practice. That concept is branching."