@Sthiss it can vary a lot for people. In short it is how much you can see. How wide your view is. Although usually less important in 3rd person games it can be a killer for some people in FPS type games as it can cause severe headaches and eye problems.
TotalBiscuit is a major proponent of FoV options in games as he finds narrow FoV too painful to actually play. Any of his videos about FPS/3rd Person games will usually mention it.
A clear benefit I could see currently would be chasing the Q's around the Academy etc. You would see if they spawn off to your side better with a wider FoV.
Most console FPS have a FoV restricted to around 65. Most good FPS should be around 90.