Unity Lenses and Scopes
The Dash is one of Unity’s main features. It allows users to search for information both locally and remotely using Lenses. Each Lens is responsible for one category of search results for the Dash.
The Lens alone is not very useful, because the Lens doesn’t perform the search. Instead, it relies on one or more scopes, which are the actual search engines, to return the search results.
In the terminology section of this chapter, we looked at the music Lens. This Lens has two scopes, which means that four processes are involved in searching the music category for content: the Dash, the Lens daemon, first Scope daemon, and second Scope daemon.
As a user, you won’t even notice the complex process the Lens performs to keep everything in sync. You can just enjoy the benefits of being able to quickly search various categories of information.
It seems that everyone has a favorite Unity Lens. By default, Unity comes with the following Lenses: Applications, Files, Music, and Video.