Sometimes you just want to enable Wifi on your Raspberry Pi without leaving your laptop or desktop. I get it.
Luckily Raspbian has made this really easy. You just need to add a file
wpa_supplicant.conf to the root of the SD card.
The file contents look like this:
ssid="your network's Wifi name here"
psk="your network's Wifi password here"
Then eject your SD card and plug it into the Pi. It should automatically connect to your Wifi.