That's the simplest definition of a graphics card
I couldn't have put it any the better but just in case the OP is wondering that, my mobo is capable of doing that (putting Pictures on the monitor), I'd just like to elaborate a little.
A Graphics Card is a piece of hardware that enables the computer to manipulates the graphics requirements of a particular program. For example, the Games that's we play on the PC require graphics processing which is Processor straining thus a Graphics Card takes over the load. So basically a Graphics Card helps in calculating the graphics of any given program.