[BroadHopper]

I could write a book on these. As well as single vs dual drives.

Trims adjust the 'attitude' of boats. I think of engine trim to adjust porpoising and bow steer. Engine trim also adjust for the bow rise when accelerating. Once I get to a cruising speed, I adjust the engine trim to level the boat to an optimum comfort level base on speed and condition of the chop.

Trim tabs are used to adjust for the port/starboard attitude of the boat. If the boat is lower on the port side than increase the port tab. Bennett trim tabs are wire so that when you lower the port button it does the opposite, it lowers the port trim and rise the starboard. And vice versa. Increasing both tab buttons lowers the trim.

As in Dave reply above, you can use the trim tabs to adjust the attitude of the boat when approaching a rough wake. depending on the type of hull, increasing the trim tab buttons can make the boat 'plow' the wake. Deep vees prefer to slice the wake under the driver like a knife.

I can go on and on, but that can be discuss over a beer at the NAZ. Anyway I think you get the drift.