Processing has a loop that runs every frame, in which you redraw the whole scene each time. So for a Tetris game, on each frame you'd draw all the blocks in their correct position. You maintain the game state however you like, you just tell processing what to draw each frame.
In Raphael, its more like a traditional game engine. You might for instance make a new Circle (or Monster, or Hero..), and give it properties and events. The redrawing would be handled for you.
Hope that helps/makes some amount of sense. My experience here is very limited, so its possible I'm misrepresenting one or both of the libraries.
Processing has a loop that runs every frame, in which you redraw the whole scene each time. So for a Tetris game, on each frame you'd draw all the blocks in their correct position. You maintain the game state however you like, you just tell processing what to draw each frame.
In Raphael, its more like a traditional game engine. You might for instance make a new Circle (or Monster, or Hero..), and give it properties and events. The redrawing would be handled for you.
Hope that helps/makes some amount of sense. My experience here is very limited, so its possible I'm misrepresenting one or both of the libraries.