Atlas also named Sprite Sheet, it's a common asset in game developing. Atlas is generated by tools. The tools will combine many images into a large image and create an index file (such as plist). Altas asset contains plist & png is supported by Cocos Creator. Here is a image of an Atlas asset:

atlas sheep

Why using Atlas

Advantages of Atlas:

Here is a video from CodeAndWeb, it will show you What is a Sprite Sheet

Create Atlas Asset

You should prepare the original images for generating Atlas:

single sheep

Then you can generate Atlas by special tools. We suggest:

Please select plist files for cocos2d-x when export atlas by the tool. Then you will get plist & png with the same name:

atlas files

Import Atlas

Drag plist & png files into Assets Panel at the same time. Then you can use it in Cocos Creator.

Atlas & SpriteFrame

In the Texture Document, we introduced the relationship between Texture & SpriteFrame. When Atlas asset imported, here is also a triangle icon beside the Atlas asset. Click it to expand Atlas asset. There will be many SpriteFrame sub-assets, each one can be used separately.

sprite frame

Continue on to read about Trim.