For WPA Wifi, edit the file /etc/wpa_supplicant/wpa_supplicant.conf
+as root.
Example:
+ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
+update_config=1
+country=FR
+
+network={
+ ssid="MY_SSID"
+ psk="MY_PASSWORD"
+ key_mgmt=WPA-PSK
+}
+Replace MY_SSID
by the name of the Wifi network and MY_PASSWORD
+by the password of the Wifi network.
Multiple networks can be declared, the one with higher priority will +be used if possible:
+ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
+update_config=1
+country=FR
+
+network={
+ ssid="MY_SSID"
+ psk="MY_PASSWORD"
+ key_mgmt=WPA-PSK
+ priority=1
+}
+
+network={
+ ssid="MY_SSID2"
+ psk="MY_PASSWORD2"
+ key_mgmt=WPA-PSK
+ priority=2
+}
+