Operation is a subclass of
NSOperation and is used to perform work on an instance of
OperationQueue which is a subclass of
Operation itself however is an abstract class and should always be subclassed to perform specialized work.
What do we mean by work? This can be anything, for example number crunching, data processing, parsing or retrieval, view controller presentation, or just about anything.
The framework provides the basic
OperationQueue types, the former of which will often be subclassed in applications. It also has other helper types, which are "building blocks" which when used together with
Operation subclasses allow for advanced usage. On top of this there are a number of "feature" operations. These are
Operation subclasses which can be used directly and perform commonly needed functionality, like
Updated less than a minute ago