Some later model wireless routers have the Password (ie.Encryption key) and the SSID already configured in the wireless router and this information is printed on a label on the bottom of the router.
These settings can be used to configure the wireless card and wireless adapters in your computer/laptop/tablet.
If these settings do not suit you, then it can be changed to suit your requirements.
The encryption key secures your data and wireless connection from unauthorized access.To configure the wireless settings in the router, connect a LAN cable from your computer to the wireless router, then open a Browser on your computer and enter the router's configuration IP address, then enter the admin login and password and then go to the wireless settings and configure the SSID and Encryption key.
The router's encryption key can be a Passphrase or the WEP or WPA or WPA2 key.If you use the Passphrase method select either WEP or WPA or WPA2 to generate the encryption key. You can enter the WEP or WPA or WPA2 key with 8 to 63 ASCII characters or 64 Hex digits.
Most people use Passphrase which is easier to remember eg. I was born in January 1988.
The strongest and latest security is WPA2, the weakest and oldest is WEP. To connect to your wireless router from the computer/laptop, configure the wireless card in your computer/laptop with the router's wireless settings ie SSID, plus the WPA or WPA2 encryption key. Then computer/laptops can communicate with your wireless router. http://www.fixya.com/support/r10267861-network_security_key