When you sign up for TELUS internet you will receive a device called a gateway - a two-in-one modem & router combo. Bridge mode is a feature that allows a user to shut off the router side of the gateway (i.e. WiFi), and use a 3rd party router in its place.
TELUS currently only offers bridge mode on 3 gateway models - the T1200H, T2200H and T3200M. The main difference between these two models is that the T1200H is a single line gateway while the T2200H is a copper bonded gateway, used for higher speed plans where two lines are required.