The bed-in procedure is a series of stops from a particular speed that help provide an even layer of friction material around the rotor and ensure that layer properly cures so that your new pads and/or rotors work at their best and don't suffer any cracking or other damage. Skipping the break-in or bed-in procedure can cause friction material to deposit unevenly which will then cause uneven levels of heat on the rotors surface, inconsistent bite and stopping power, and all sorts of other fun problems that you really don't want to run into while you're trying to bring your truck to a safe and complete stop. The uneven deposits can cause excess rotor and pad wear, warped rotors due to uneven heating, and even stress cracks. These are naturally "bad things" so make sure you get your bed-in procedure completed to the brake pad/rotor manufacturer's specifications.
Bed-in and breaking-in are basically the same throughout our brake component manufacturers, with maybe one or two minor differences. Power Stop's break-in procedure is as follows: five moderate to aggressive stops from 40 miles an hour down 10 miles per hour in rapid succession without letting the brakes cool down before stopping and accelerating again. After that first cycle, perform five more moderate stops from 35 miles per hour down to five miles per hour without letting the brakes cool. Once both sets of five stops are done, allow your brakes to cool down by driving for five minutes or more without excessively heating the brakes or coming to a complete stop in order for your new layer of friction material to properly cure. Once all that's completed, your break-in/bed-in procedure is complete.