
Not only are they responsible for drawing ordinary 2D graphics such as windows and documents, but the best modern graphics cards can generate realistic, high-resolution 3D graphics in real time without needing that content to be pre-rendered. They perform an enormous number of calculations and are typically the most sophisticated components in a computer - particularly high-end graphics cards optimized for gaming and advanced graphics processing.
Modern graphics cards are extremely sophisticated devices that in some ways behave like stand-alone computers. This kind of graphics card is replaceable so it can be upgraded as newer graphics cards are developed and helps keep a PC from becoming obsolete.
A discrete GPU is mounted on a graphics card that slips into a computer's expansion slot on the motherboard. These graphics typically have modest performance and don't perform well for tasks like games or professional graphics production. You'll find this in laptops and inexpensive desktop PCs. An integrated GPU is built into the motherboard and cannot be upgraded or replaced. A graphics card is sometimes commonly referred to as a graphics processing unit, or GPU, but in reality the GPU is just a component (albeit the primary, defining component) of the graphics card. A graphics card looks like a smaller version of the computer motherboard - it's a printed circuit board that has a processor, RAM, and other components.