What are the sitelinks and how to get some?

What are the sitelinks and how to get some?

Sitelinks are additional links displayed by Google in their results pages. From 1 to 8 links can therefore be provided.
12 links max.

They are supposed to improve the user experience by making the navigation easier, so they can access an intern page they want to visit in only one click.

The display or non-display of these additional links is managed by Google's algorithms that determine if their addition is relevant for the user.

Some sitelinks seem to appear when Google is pretty sure that the website displayed in first position is the one wanted.

Today, we notice that the display of sitelinks has been reduced to a single line. These "one-line sitelinks" can concern a page in first position as well as less well ranked pages.

As there are so many variations, it is hard to know how Google determines which links to display and with which text anchor.

However, Google seems to particularly like the texts anchors used on the most visited websites and pages. A good internal linking might also contribute