Why do I lose Wi-Fi when I leave the house on my iPhone?

Wi-Fi comes from a little device in your house called a router. It produces the Wi-fi signal and connects to your ISPs internet service.

When you are far enough away from the router you have no Wi-Fi because there;'s a limit to how far the router's signal can travel.

Smart Phones also have a connection to cellular data, this lets you connect to the internet through your cellular service providers cellular towers wherever you are and wherever there's a good enough cellular signal coverage.

There are also public Wi-Fi hotspots you can connect to when in certain places like coffee shops, restaurants, hotels, libraries etc...

WiFi has a range of about 100 feet from the router. When you lose your WiFi connection, the phone should automatically connect to cellular data.