Do NOT use alone. Do NOT use with web-frameworks or libraries like [reactjs], [django] or [flask]. Use for questions about web applications, where a more specific tag isn't applicable. Use with a appropriate language tag([java]) and the specific aspect of web-application, the question is about: http method([post],[get]), errors([http-status-code-404]), client-server communication ([client-server]) or server errors.
A web application is a client-server application that bases the communication on the HTTP (http) protocol. Often a third layer implements data persistence through a database.
The client side runs in a web browser that sends the http requests, receives the responses, renders the response's content (usually a html page, but also video streams, or applets). The heavy-lifting is done by scripts or compiled code on the server side. Some examples of web applications include Google Calendar (google-calendar), Zimbra (zimbra), and Office Outlook Web Access.
