You can define whether a layer is:

• Snappable/unsnappable.
• Locked/unlocked.
• Visible/invisible.

When a layer is snappable, you can snap new objects to objects in the layer. When a layer is locked, you cannot select or modify any of the objects in the layer. When a layer is visible, all objects in it are displayed in the workspace (conversely, when it is invisible, the objects are not displayed).