Version control
A version control system is useful when working on a collection of files that evolves over time, in particular if several people are modifying the files. For example, version control is often used in software projects to store the code in a way that several developers can access and contribute to the code without the need to send files by e-mail etc. Another example is when you are writing a paper with your colleagues and you need to efficiently and safely share your additions to the paper. A version control system also keeps track of the history of your contributions; most version control systems can be used to retrieve the state of your files as of a given date. This means that there is no need to create local back-up copies. To make it short and sweet: version control means you can relax.
Git
Git is currently the preferred version control tool at the department.
Talk to Anders Nilsson in order to have a repository for your files set up, or if you want to know more about version control.
Subversion (deprecated)
The version control system Subversion is installed on one of our servers. Currently, it is used for a number of research projects, some master's thesis projects and for the projects in the Project in Automatic Control course. However, since git reached maturity a couple of years ago there is very little reason in creating new subversion repositories unless you have good reasons to do so.