Can you explain how WebDriver works for browser automation?

WebDriver is an interface for browser automation that allows programmatic control of a browser as if a user were operating it. The mechanism is based on a client-server architecture:

1. The client (test script) sends commands to the WebDriver API (for example, open a page, click an element) via HTTP requests.
2. A special driver for a specific browser (for example, ChromeDriver for Chrome) receives these commands and translates them into native browser calls.
3. The browser executes the commands and returns the result back through the driver to the client.

Thus, WebDriver provides a browser-independent way of automation, using the JSON Wire Protocol or W3C WebDriver standard. This allows writing tests that work with different browsers without changing the code.