Describe a web navigation tool that is used for a user to navigate to different pages on a website or to external sites from a specific site.

A web navigation tool that is commonly used for users to navigate to different pages on a website or to external sites from a specific site is a hyperlink. Here's a step-by-step description of how it works:

1. Hyperlinks are usually highlighted or underlined text or images on a webpage. They can be identified by a change in the mouse cursor when it hovers over them.

2. When a user clicks on a hyperlink, the browser sends a request to the server hosting the destination webpage. This request includes the URL (Uniform Resource Locator) of the destination page, which is embedded in the hyperlink.

3. The server responds to the request by sending the data for the destination webpage back to the user's browser.

4. The user's browser then renders this data into the visible webpage that the user sees.

5. If the hyperlink leads to a different part of the same webpage (an anchor link), the browser simply scrolls to that part of the page.

6. If the hyperlink leads to an external site, the browser will open a new tab or window (depending on the user's settings) and display the destination webpage there.

In this way, hyperlinks serve as a fundamental navigation tool on the web, allowing users to move between related topics, sources, and sites with ease.