[Christ]

That's pretty much it, exxcept that keeping on the throttle while up shifting increases the rpm while the goal of upshifting is to lower rpm. End result is lots of heat, while the clutch disc acts like a brake, using the vehicles mass, thus resistance to acceleration, to slow the engine to a 1:1 ratio with the input shaft of the transmission.

There are times when this action is beneficial, but we won't discuss those now.

As another thought - it's actually much safer to use high rpms to slow down than to rev high under load. Slowing places less stress on the engines internals than accelerating.

Consisting takes advantage of otherwise wasted energy, frictional losses and pumping losses, gear and drive train losses, to slow the vehicle. Done properly, it also greatly d saves on brakes. An added bonus is that by teaching yourself to drive proactively enough to downshift and use the brakes only when absolutely necessary, you also will be a safer, more economical driver.