An applet is a small application designed to perform a specific task within a larger program or environment. Typically written in programming languages like Java, applets run in a web browser or as part of a software application. They are often used to provide interactive features on websites, such as animations or games. Unlike full applications, applets are lightweight and can be easily downloaded and executed. They rely on a host application or browser to function, which helps ensure security and compatibility. Applets have become less common with the rise of modern web technologies like HTML5 and JavaScript, which offer similar functionalities without the need for additional plugins.