From BlenderWiki

Scenes

Scenes are virtual locations where objects are located and animated action takes place.

Many still shots and short animated works will be located in a single scene, but it is possible to have several scenes within the same Blender file. As such, scenes may use one another’s objects/data, or be completely separate from one another. You can select and create scenes with the SCE drop-down button in the User Preferences window header (Screen and Scene selectors).

To understand more fully what multiple scenes means in Blender, please have a look at “Blender’s Library and Data System”.

Scenes configuration

Adding a new Scene

You can add a new scene by clicking () on the scene selector, and selecting ADD NEW. When you create a new scene, you can choose between four options to control its contents (Add scene menu).

To choose between these very important options, you need to clearly understand what “Object” vs. “ObData” actually are. “ObData” is geek-speak for “object data”. Each Blender graphic element (mesh, lamp, curve, …) is composed from two parts: an object and some obdata. The object holds information about the position, rotation and size of a particular element. The obdata holds information that is specific to that particular type of element, e.g. meshes, materials lists, and so on. Each object has links to its associated obdata, and a single obdata may be shared by many objects.

The four choices, therefore, determine just how much of this information will be copied from the currently selected scene to the new one, and how much will be shared (“linked”):

• Empty – Creates an empty scene (nothing is shared nor copied).
• Link Objects – This is the shallowest form of copying available. This option creates the new scene with the same contents as the currently selected scene. Nothing is copied: instead, the new scene contains links to the objects (and hence, implicitly, to the obdata) in the old scene. Therefore, changes in the new scene will also modify the “linked” one, because the objects used in the two scenes literally are the same.
• Link ObData – This will create new, duplicate copies of all of the objects in the currently selected scene, but each one of those duplicate objects will have links to the same meshes, materials, and so on (the “obdata”) as the corresponding objects in the original scene. This means that you can change the position, orientation and size of the objects in the new scene without affecting those in the other one. But any modification to the meshes, materials, and so on (the obdata) will affect the other scene. This is because a single instance of the obdata is now being shared by the objects in both scenes.
• Full Copy – This is the deepest form of copying available. Nothing is shared. This option creates a fully independent scene with copies of the currently selected scene’s contents. Every object in the original scene is duplicated, and a duplicate, private copy of its obdata is made as well.

When you choose one of the shallow copy above, if you want to make changes to an object in the new scene independently of the objects in the original one, you’ll have to manually make the object in the new scene “single-user” (U). The menu that pops-up allows you to create a single-user copy of the object and/or its various obdata. Once again, please have a look at the data system pages for more details.

Deleting a Scene

You can delete a scene by using the “X” “delete datablock” button () on the Scene selector, and confirm by clicking Delete current scene on the pop-up dialog box (see Screen and Scene selectors above).