How do you engage Quick Look?

The Privacy pane of Security & Privacy preferences can be used to allow or disallow applications' access to Location Services, Contacts, Calendars, Reminders, social network services, and Accessibility application access.

Quick Look is engaged by simply pressing the Space bar when a document is selected. Applications that support Quick Look include the Finder, Time Machine, Mail, and most open and save browser dialogs.

The Activity Monitor application is used to monitor open processes and applications.

You can use the System Information application to easily scan all the appropriate application locations and return a list of installed applications.