Simple DirectMedia Layer is a cross-platform development library designed to provide low level access to audio,
keyboard, mouse, joystick, and graphics hardware via OpenGL and Direct3D.

SDL is a wrapper around operating-system-specific functions that a game needs to access.

It provides a common framework for accessing these functions for multiple operating systems (cross-platform).  SDL provides support for 2D pixel operations,
sound, file access, event handling, timing and threading. It is often used to complement OpenGL by setting up the graphical output an
providing mouse and keyboard input, since OpenGL comprises only rendering.

