What is a Blit in SDL?

Question

In the SDL wiki it says

Use this function to perform a fast blit from the source surface to the destination surface.

However that

Answer 1

Official code sample

Intuitively, it means to "draw a sprite on top of another surface".

This operation can be GPU accelerated with SDL_Texture + SDL_RenderCopy.

Have a look at http://hg.libsdl.org/SDL/file/e12c38730512/test/testsprite2.c for an example, in particular the comment:

/* Blit the sprite onto the screen */
SDL_RenderCopy(renderer, sprite, NULL, position);

which explicitly says that SDL_RenderCopy is a way to blit.

In that example, the texture is created and sent to the GPU memory only once, and from then on it is reused efficiently, see also: Difference between surface and texture (SDL / general)

When I run this example on Ubuntu 15.10, nvidia-settings says that GPU usage is goes to 100%, and I get a much higher FPS than by drawing pixel by pixel to the screen, so it is GPU accelerated.