Your Bell SIM card connects your device to the Bell network, giving you access to voice and text services, and depending on your device, Internet and select data services. It also contains your mobile identity. It stores your phone number, important account information, contacts and text messages. Your SIM card remains active as long as you subscribe to Bell, and you can move it from one device to another whenever you like.
If you have a non-Bell phone that you'd like to use with Bell, you'll need to get a Bell SIM card.