It’s a Game development framework.
What does it do
- Helps you draw images (and play sounds)
- Checks for player input
- Other gamedev tools like collisions, creating text, timers etc.
Surfaces
- Display surface. The game window. Anything displayed goes on here. Must be unique, is always visible.
- (regular) Surface. Essentially a single image (something imported, rendered text or a plain color). Needs to be put on display surface to be visible. Flexible amount, only displayed when connected to the display surface.
Origin point (0,0) is a top-left of the window.