SEARCH
Two types of search query syntax available for searching a view
Two types of search query syntax are available for multiple term searches:
Scopes are the names of collections of searchable content. The default scope that initially displays will be the All scope of whichever tab page is currently open. For example, if your Mail tab is active, the "All Mail" scope would be visible and its name would display as ghost text in the Search entry field.
Clicking the triangle next to the Search icon opens the Search scope drop-down menu. In addition to the All Mail, All Calendar, and All Contacts scopes, you might see: