Whether you connect to these networks with your Mac, iPhone, or iPad, miraculously, your devices will remember these networks and sync them via iCloud - so your other Apple products can access them too, if you use iCloud Keychain. If you travel regularly with your Mac or iOS device, you likely find yourself connecting to new Wi-Fi networks: at airports, in train stations, in hotels, restaurants, pubs, or at clients’ offices.
How To How to Remove Wi-Fi Networks from Your Mac and iOS Device