Final answer:
An interface is a point of interaction between two entities, defining communication methods, while a gateway endpoint is a point that connects and translates communication between different networks or services.
Step-by-step explanation:
The difference between an interface and a gateway endpoint is fundamentally about the roles they play in network communications and the context in which they are used. An interface refers to a shared boundary or a point of interaction between two entities, such as between hardware and software, or between two different software modules. It defines the methods and properties that can be used for communication. On the other hand, a gateway endpoint is a network point that acts as an entrance to another network. It serves as a passageway and translates communication between different networking protocols, making it possible for data to flow between different networks or services.