Web apps are applications that run on a web server and can be accessed through a web browser. Unlike traditional software that needs to be installed on a computer, web apps allow users to interact with them online, making them accessible from any device with internet connectivity. Examples include Google Docs and Facebook. These applications use technologies like HTML, CSS, and JavaScript to create dynamic and interactive experiences. Web apps can be used for various purposes, such as productivity, communication, and entertainment, and they often update automatically, ensuring users always have the latest features without needing to download anything.