Interface

Meaning

An interface is a contract that lists the methods a class must provide without describing how they work. The PHP manual says interfaces specify which methods and properties a class must implement, and a class may implement more than one interface. This lets the rest of an application treat different classes in the same way; several payment gateways, for instance, could all promise a method that starts a payment. Interface methods must be public. See also: Class, Trait, Inheritance, and the guide PHP Functions and Object Oriented Programming Concepts.