An API (Application Programming Interface) is a set of rules and protocols that allows different software programs to communicate and share data with each other. APIs act as bridges, enabling applications, websites, and services to interact seamlessly, even if they are built on different technologies. For example, when a weather app displays local forecasts, it often uses an API to retrieve data from a remote server. Because APIs can provide access to sensitive information or system functions, they are frequent targets for cyberattacks. Proper security measures are essential to protect APIs from unauthorized access and data breaches.