What is "web-application"

In computing, web applications are, in general, computer systems designed for use from a browser, through the internet or applications developed using technologies web, as html, javascript and css. Can be run from a server http (Web Host) or locally, on the user’s device.

One web application is also defined as being all which is processed on some server. For example a e-commerce, where it is necessary a page assembly processing that will be loaded to the user, applying its business rules according to each request; so it is a applying, not simply a website.