Android 4.2 introduced a major change for tablets: multi-user profiles. This allows each member of the family (or organization), to have their own profile, complete with app, homescreen, and setting independence. Today, with Android 4.3, Google has taken multi-user accounts to the next level with restricted profiles. Essentially, this allows the tablet owner to have granular control over the other user accounts on the device.
For example, let's say you're a parent and you share a tablet with a young child.