Animated and automatic change of the number on the site, depending on the "control number"?

Question

JavaScript

There is a number, let's call it control. When it changes, the site should automatically duplicate it without refreshing the page.

For example, the control number = 10, and the site indicated the number 10, later the control number became equal to 11, and on the site without refreshing the page, this number also changed to 11.

Maybe there is such a JS or a plugin, or something else?

Like this format:

Answer 1

jquery ajax requests. Let's say it makes requests every second and if the value has changed, then updates