Normal Links
When a normal hyper link is clicked, an HTTP request goes to the server. Till a response is obtained, the old page is displayed, and you can work on that page (read / scroll, click links etc). If you click a link during this time, a new HTTP request will go, closing the old connection or neglecting the response of the old request. A new page is loaded, replacing the old one. The user will experience a reflow or refresh of the page if the content and layout is very similar to the page and the new page loads quickly. Otherwise, the user will have to wait till the page loads. It might take some time for the page to load.
These links are not under direct script control. The browser controls such requests to the server. And the browser is responsible for handling such links. This is quite different from how a request under script control works.