What's included in the license?

The basic license bundle is a V-Ray Workstation which includes one V-Ray Graphic User Interface (GUI) and one V-Ray Render Node 3.0. 
The GUI license in your bundle unlocks the V-Ray menus in your 3D host platform - it enables you to use the V-Ray plugin in the host platform interface, to navigate V-Ray menus, use materials, etc. This license is not used for rendering. Only the V-Ray Render Node 3.0 is used for rendering - when you start a render job it always takes a V-Ray Render Node license, regardless if it is on your workstation or on some render slave machine. In order to use more computers for rendering, you can purchase additional V-Ray Render Node 3.0 licenses.