I found this under Options>Security Options>Firewall. It's disabled by default. Should I switch it on? What does it do?

I'm thinking this is only for wifi use. Yes?

it's for wifi or edge use. with the firewall disabled, some apps like opera mini will ask for permission to access the network each time you use them. with the firewall enabled, it will only ask once.

Okay, so is it good practice to use it? I have Edge and don't use Opera.