What is the official name and nature of the panels that are sliding upwards in web browsers I think the title sums up pretty good what I am asking but, here is a screen capture of the particular type of in-browser panels I'm wondering about

I don't mean the ones android system shows when there is no default app setup. I mean, in the browser itself. I don't imagine they are the same are they ?
I've seen the Android dev documentation about &quot;SlidingPaneLayout&quot; which sounds similar. Except, the one I'm interested in is not &quot;dismissable&quot; or &quot;resizable&quot;. It actually takes over the flow and darkens the background until the user either selects an option it offers or, swipe kill the browser tab.
Are those part of the webwiew? I'm wondering what term I need to look for in order to get the details about those panels.
Or, if I am wrong in anyway here, maybe someone could just give me a brief explanation? would be much appreciated
Search results on google mostly brought rants about a completely different type of browser notification so I figured i'd try asking here.
Your question made me search and it's  modal bottom sheet

are an alternative to inline menus or simple dialogs on mobile and provide room for additional items, longer descriptions, and iconography. They must be dismissed in order to interact with the underlying content.

(Emphasis added)