In Settings, what does the description below "Ask to join networks" indicate?

Your Mac's wifi controller scans the environment to identify wifi access points and hotspots around it. The toggles allow to decide if:

• The Mac does nothing when it identifies an access point or hot spot. If you want to join a network you need to manually select it from a list of networks the Mac builds from scanning the environment (if you've previously joined a network - i.e., it is "known", the Mac will automatically join it for you); or,
• If the Mac sees an access point or hotspot, and you aren't currently connected to a network, the Mac will pop up a notification saying it has found one and asking if you want to connect to it.

There are two toggles - one for network access points (Wifi routers broadcasting Wireless SSIDs) and one for hotspots. The behaviour of each toggle is the same - off means manual connection, on means it asks you if you want to connect.

If you were to toggle them on, a prompt will appear when a nearby network or hotspot is discovered, asking if you want to join it. You would need to provide its password (obviously).

OP wrote " What about this one? Does it describe the current situation " >> No

OP wrote " what would happen if I toggled it on? " that question has been answer in the previous posting

The wording is awkward for sure.

FYI, you can always toggle the switches and see how the text changes.