Can someone please explain to me how to animate a sprite, using an image with a set of poses? For example is it possible to specify one part of an image, or do i have to use seperate image files for each pose? And lastly, how exactly would one go about animating a character frame by frame, so to simulate walking. As in you show the sprite's legs moving, to make it look more realistic.

I've figured out how to move an image across the screen, but I don't even know how to specify the coordinates in which the image will be. Jeez I'm bad at this. Can someone please attempt to help me? Or can you lead me in the right direction?