Reports
Reports come in two kinds, and they behave differently. Built-in reports are read-only and addressed by a string key such astotalContacts; custom reports are ones you create, addressed by an ID, with the full create, update and delete cycle. Either kind returns its configuration separately from its rows, so you can see what a report contains before paying the cost of running it. They exist to answer questions across your data without querying it directly. See Reporting in the Help Center.