This is my attempt at making a raycaster rendering engine completely on my own without libraries to help me. I'm also not reading on how raycasters work, I'm figuring out how to do things by myself.
A raycaster engine uses rays to tell what it should render on the screen. Specifically it uses a two dimensional map to make a three dimensional world. Games like DOOM use raycaster engines.
Here's a working example of a raycaster that I'm using as a model (without reading the code): mdn.github.io/canvas-raycaster/