What is the site element called?

Question

JavaScript

Here at Yandex, when scrolling, a search bar appears.
On ozone, when scrolling, the menu also remains on top.
Or on metromap.ru - the same nonsense.

What is the name of this feature \ technique \ horseradish?
It is worth considering that it will not scroll immediately. but from a certain place on the page.
So, what to google and read to do the same? (if I know the name, I'll google it myself).

Answer 1

imakewebthings.github.com/jquery-waypoints/sticky-elements/
imakewebthings.github.com/jquery-waypoints/#examples
I think you will understand the docks, and there are examples there

Answer 2

It is called a fixed block. It's done like this

HTML: <div id='block'>Блок</div>
CSS: #block {position: fixed;}

Answer 3

you can call it a "floating block"