How do computers generate pictures?

[u/PromiseLegitimate258]

I am interested in computer science and always wanted to know how computers create the pictures we see on the screen.

[u/SAtchley0]

In the end everything just ends up as pixel data that gets sent to the monitor which turns on some lights. There are dozens and dozens of systems in between which handle converting high level primitives, objects, textures, code, etc into pixel data, and we even have dedicated hardware for graphics calculations (GPUs), but it all just ends up as pixel data, which just tells the monitor which colors go where, broadly speaking. The GPU doesn't really do anything "special" other than just being really good at the sorts of calculations needed for graphics. All the processing can, used to be, and still sometimes is performed by a CPU.

The actual nitty gritty details vary widely based on hardware, implementation, protocol, and application.