Linux is a free operating system which works on several different computers. Because it is free, there are also several separate providers for it, each of which offer slightly differing solutions. Linux is mainly used in different servers, but there are also desktop versions of it.

Because Linux has not attained great user popularity, it is a rather safe option concerning information security as it faces attacks fairly rarely. In addition, its faults are fixed relatively quickly, as anyone can fix the faults thanks to the open source code.

More information on Linux and its different versions can be read on Wikipedia at https://en.wikipedia.org/wiki/Linux