From Sega Retro
The Go button appears on all pages in the standard skin, next to the search button. The function of the go button is to display a page directly, instead of first having to select it from the search result page. In other words, it allows you to quickly navigate from page to page without following links.
To view a page, just enter its name and click "Go". The Go button is more complex than it looks. It works as follows:
That is, for example, if both a talk page with the title and a normal page exist, the normal page is viewed. If there is no match, continue.
Try a full text search for the entered words and display the search result page as it would be shown if you clicked the "Search" button.
If you use the Go button wisely, it will allow you to quickly jump to your most frequently used pages. It is also a good idea to use it for unambiguous searches — if a direct match fails, it will always fall back to the normal search anyway, and if it succeeds, you are immediately taken where you want to go. In general, the go button generates little server load, and therefore usually remains functional even if the fulltext search is deactivated for performance reasons.