The Canvas API is a web-based programming interface that allows developers to create and manipulate graphics directly in a web browser. It provides a set of functions for drawing shapes, text, images, and animations on a rectangular area known as a canvas. This makes it useful for creating dynamic visual content, such as games, charts, and interactive applications. The Canvas API is part of the HTML5 specification, which means it is widely supported across modern web browsers. By using JavaScript, developers can access the canvas element and control its properties, enabling rich visual experiences without the need for additional plugins or software.