A Web API (Application Programming Interface) is a set of rules that allows different software applications to communicate over the internet. It enables developers to access specific features or data from a service, such as retrieving information from a database or sending data to a server. Web APIs use standard protocols like HTTP to facilitate this interaction. Web APIs are commonly used in web development to enhance functionality and user experience. For example, a weather API can provide real-time weather data to a website, while a payment API allows online stores to process transactions securely. This makes it easier for developers to integrate complex features without building everything from scratch.