Ood matlab - XFCE


I am a student working for PSC, and I am trying to get Matlab working for Bridges here at PSC. I am trying to understand the purpose of XFCE. What is the purpose of XFCE? If I am not mistaken, vlgrun already spawns a window where I can run matlab remotely. XFCE is a desktop environment, so why would I need that if virtualgl already accomplishes what I need?