SSID is simply the technical term for a network name. When you set up a wireless home network, you give it a name to distinguish it from other networks in your neighbourhood. You'll see this name when you connect your computer to your wireless network.
WPA2 is a standard for wireless security. Your WPA2 key is an alpha-numeric security password that is required to access your Internet connection. Anyone without this password cannot access your Internet connection.
Where do I find my default SSID and WPA2 keys?
Your network name (SSID) and network key (WPA2) are located on a label that's either on the bottom or on the side of your modem.