buggy's are typically designed for racing. they are low to the ground and stable for rocketing through turns. they can take some jumps but typically not huge jumps. Monster trucks have a high center of gravity and are designed to take a TON of abuse. BIG JUMPS and wheelies are possible with a monster truck. Monster trucks also race but the high center of gravity limits how fast they can make it through corners. Of course you can set up a buggy for bashing and a monster truck for racing, but in general that's the big differences.