Low-level rendering
Besides the high-level convenience classes sf::Sprite, sf::Text and sf::Shape, SFML provides a low-level graphics API which is more complicated to use, but allows more flexibility. In the next section, we are going to look behind the scenes of rendering and discuss corresponding techniques as they are implemented in SFML.
OpenGL and graphics cards
The graphics card architecture consists of many components. Notable are the graphics processing unit (GPU), which performs computations on the graphics card, and the video memory, which stores data such as textures. In contrast to their counterparts CPU and RAM, graphics cards' components are highly optimized to process 2D and 3D graphics.
SFML is built on top of the Open Graphics Library (OpenGL). OpenGL is, like DirectX, a specification of an interface to the graphics card. Operating systems provide an API written in C that allows applications to access graphic card functionality. Newer graphics cards support higher OpenGL versions...
