The iPhone can browse the Web over your cellular connection, but whenever possible, you should connect to Wi-Fi to . Wi-Fi is usually faster and more stable than a cell connection, as well. Every time you connect to a new wireless network -- when you first buy your phone, when you replace your router (or change its password), when you visit a friend's house and so on -- you need to pick a network in the Settings app. Afterward, your iPhone reconnects to the network whenever it's in range.
Connect to a Wireless Network
Open the iPhone Settings app and tap Wi-Fi. If the Wi-Fi slider is off, tap it to switch it on.
Tap the name of the network you want to join. If you don't know the name of the wireless network in your home, look for a sticker on the back or bottom of the router.
Enter the password for the network and tap Join. Unlike some other devices, you don't need to know or input the type of security your router uses when picking a network off the list.
After the connection is made, the network icon in the status bar changes from displaying your cellular data connection — such as 3G, 4G or LTE — to displaying the Wi-Fi connection strength.
If You Don't See Your Network
The iPhone usually shows every network in range, except for hidden networks. If your network doesn't show up in the list and you're sure it's running, enter it manually.
Tap Other at the bottom of the wireless network list and enter the network name () by hand.
Tap Security and pick the security type for the network. As of iOS 8, the iPhone supports , , WPA Enterprise and WPA2 Enterprise security systems. For open networks, choose None. After picking a security setting, press Back.
Enter the network password and tap Join.