This is the documentation for the Joomla 3 version of Tabs.
There is currently no Joomla 4 version of Tabs.
Tabs for Joomla 3 is based on the Bootstrap tabs functionality, so it uses and needs the Bootstrap 2 framework (styles and scripts) that comes with Joomla core.
This means that Tabs will only function correctly if your template allows the Bootstrap 2 framework to be loaded and does not cause conflicts with the jQuery and bootstrap javascripts.
Tabs are not very user friendly for mobile devices, because of the horizontal space they need. That is why Tabs for Joomla 3 has an alternative view for mobile screen sizes. On this demo page, that option is switched on. So the tabs on this page are not visible as actual tabs, but as a list which will link to the different sections.

Tabs is a Joomla! system plugin that allows you to display content in tabs.

It also comes with an editor button plugin.

With Tabs you can make content tabs anywhere in Joomla! - including within articles, inside modules, or even 3rd party components and template overrides.