This is a site feature that shows an Up-button in smaller viewports to help the visitor to easier get back to the top of the current page.
Since this is a feature that impacts the entire site, you should make sure that you really want it either on or off before you change its current status.
The “Up” button will be visible once the visitor scrolls past a certain amount of pixels (900 px by default), and starts an upward scroll motion. It then disappears again if the visitor clicks on it, or starts to scroll downwards again.
Do's and don'ts
- Do not use this feature on a site with only short pages, since it might be more annoying than helpful in that situation.