Part of macOS

`airportd`Wi-Fi

○ Leave it

Runs Wi-Fi.

What it is

Connects to Wi-Fi networks and keeps the connection healthy.

If you stop it

Wi-Fi drops for a moment while macOS restarts it. Leave it.

○ Leave it. Part of macOS, or something that starts again by itself. You never need to close these.

From Procession’s guide, in the words the app shows.