Within SQL-DMO, collections represent a group of Microsoft® SQL Server™ components. The meaning of the collection, the components referenced from the objects contained, is visible in the collection’s name. For example, the Operators collection contains Operator objects that reference SQL Server Agent operators.
Because collections represent the sum total of components within a given scope, altering the number of objects in the collection, by adding a new object or removing an existing one, administers a server running SQL Server by creating or dropping a referenced component.