**There is and there is not.** **Apple calls interfaces "protocols"**. When they say protocol oriented they mean programming using interfaces instead of inheritance. From here: http://www.tutorialspoint.com/objective_c/objective_c_protocols.htm > Objective-C allows you to define protocols, which declare the methods > expected to be used for a particular situation. Protocols are > implemented in the classes conforming to the protocol. From Objective-C Succintly: > In Objective-C, a protocol is a group of methods that can be > implemented by any class. Protocols are essentially the same as > interfaces in C#, and they both have similar goals. They can be used > as a pseudo-data type, which is useful for making sure that a > dynamically-typed object can respond to a certain set of messages. > And, because any class can “adopt” a protocol, they can be used to > represent a shared API between completely unrelated classes. From Objective-C for Absolute Beginners: > Apple defines a protocol simply as a list of methods declarations, > unattached to a class definition. The methods listed for protocols are > suppose to be implemented by you. So, protocol oriented programming is what Objective-C and Swift programmers call what the rest of us call favoring implementif interfaces over extending classes (inheritance).