What does @dynamic do in Objective-C? [duplicate]
Solution 1:
@dynamic means “my class will figure out how to respond to this at runtime.” Uses a runtime mechanism for an object to intercept messages it normally wouldn’t respond to. In the case where a Core Data db is used to store persistent data, NSManagedObject turns these into calls to -valueForKey: and -setValueForKey:.
Take a look at Lecture 12 (Fall 2010) of Stanford's iPhone development course.