Web App In software engineering, a web application — sometimes called a webapp and much less frequently a weblication — is an application that is accessed with a web browser over a network such as the Internet or an intranet. Web applications are popular due to the ubiquity of the browser as a client, sometimes called a thin client. The ability to update and maintain web applications without distributing and installing software on potentially thousands of client computers is a key reason for their popularity. (Source: Wikipedia)