Web application (Web app) is defined and considered as an application program that is stored on a remote server and conveyed over the Internet through a browser interface.
Do you want to start communicating with the people who are visiting your site and get to know them? The web provides a way to do so; you can ask your web visitors to subscribe to your newsletters, or to submit an application form when they request information on your products or services, or to provide details to customize their browsing experience when next visiting a specific website.
How about capturing, storing, processing and transmitting all this data to be used immediately or at a later date? We have the answer for you, web applications are those website widgets that allow this to happen, they come in the form of submitting fields, inquiry and login forms, shopping carts, and content management systems.