A programming interface is a set of rules and tools that allows different software applications to communicate with each other. It defines how requests for services or data are made and how responses are returned. This can include functions, protocols, and data formats that developers use to build software. Common types of programming interfaces include Application Programming Interfaces (APIs) and User Interfaces (UIs). APIs enable developers to access specific features or data from a service, such as retrieving information from a database or integrating with a web service. On the other hand, UIs are the visual elements that users interact with, like buttons and menus in applications. Both types of interfaces are essential for creating user-friendly and functional software.