A web client lets the user request something on the server, and shows the user the result of the request.
When we talk about clients, though, we usually mean both (or either) the human user and the browser application.
The browser is the piece of software (like Netscape or Mozilla) that knows how to communicate with the server. The browser’s other big job is interpreting the HTML code and rendering the web page for the user.
So from now on, when we use the term client, we usually won’t care whether we’re talking about the human user or the browser app. In other words, the client is the browser app doing what the user asked it to do.