Can you explain how a web application communicates with a server?

A web application communicates with a server through a process called client-server architecture. The client, or web application, sends a request to the server via the HTTP protocol. The server then processes the request and sends back a response, also through HTTP. This response can be in the form of HTML, CSS, and JavaScript, to display a webpage, or it can be in the form of JSON or XML data, which the web application can use to dynamically update its content. The communication between the client and the server is often facilitated by the use of APIs, or application programming interfaces, which allow the two systems to exchange data and commands in a standardized way.