What is an atlas?

[xByteCode]

This may be a simple question, but since I started using tk2d I have have seen atlas used many times, especially in a sprite collection. So what exactly is meant by a atlas? I know the word itself is defined as a collection of maps or charts, but can also mean the size of a drawing or piece of paper. Is that what is meant by sprite atlas, meaning the size of the sprite?

Thanks for any help and yes I am fairly new to both Unity and tk2d 

[dotty]

All your seperate sprite textures are put onto a single texture (so Unity only needs to load 1 image, instead of many images). That texture is an atlas.

[xByteCode]

Ah I see. So basically an atlas or texture atlas is like an sprite sheet, in a sense they both hold multiple images in a single image. In this case a texture is holding multiple images or sprites.

Thanks for the help dotty