API stands for Application Programming Interface. It is a set of rules and protocols that allows different software applications to communicate and interact with each other. APIs enable developers to access and use the functionalities of other software or services without having to understand the underlying code. They provide a standardized way for applications to exchange data and perform tasks, making it easier to integrate different systems and create new applications. APIs are widely used in web development, mobile app development, and various other software projects to enhance functionality and improve efficiency.