SSID is simply the technical term for a Wi-Fi 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 devices to your wireless network.
WPA2 is a standard for wireless security, and is the default type of wireless security Bell Wi-Fi uses. Your WPA2 key is an alpha-numeric Wi-Fi network password. Without this password you cannot access your Bell Wi-Fi network.
Where do I find my default SSID and WPA2 keys?
Your Wi-Fi network name (SSID) and Wi-Fi network password (WPA2 key) are located on a label that's either on the bottom or on the side of your modem.