Corona SDK includes a sprite sheet feature for constructing animated sprites. Refer to the following link for more information on sprite sheets at: http://developer.anscamobile.com/reference/sprite-sheets.
Sprite sheets are an efficient way to save texture memory. They are recommended for complex character animation or when numerous types of animations are involved.
Sprite sheets will require more coding and have more of an advanced setup. They require the construction of a large sheet of animation frames. The movieclip library is easier to get started with, and can be more rapidly used to port Flash content, since movieclip frames can be exported from Flash as PNG sequences.