Usually, a motorized board consists of the body (deck, truck, axle and wheel) and the power unit (engine or DC motor, fuel tank, battery, power-transmission system, remote controller).
When classified according to the power source, there are electric-motorized skateboards driven by batteries and DC motor, and engine-mounted-motorized skateboards using gasoline as fuel.
Generally, the advantages of an electric board include quiet and smooth cruising. But, the battery of electric board is heavy and limited in its charging capacity, which restricts traveling distance of the board. And yet another disadvantage is that boarders cannot enjoy a spectacle riding as an electric board has relatively low power-output compared to a gasoline engine.
In contrast, a gasoline-engine board allows far more dynamic riding as it has much higher output of the engine than an electric board. Moreover, different from the long-charging time of electric boards, the gasoline-engine board can get fuel at nearest gas station to run anytime.
In the case of an engine board, exhaust sound from the engine can be a nuisance. But, given that the riding of motorized skateboards falls into the category of motorized sports, the sound seems not be a big problem.
(It is like motor-cross games, formula racings and motorbike racings where exhaust sound from the engine can never be a noise.)
-Picture Images (Electric Motorized Skateboard: X-kate, BIKIKI, TAMI-NEO / Skateboard motorized by a gasoline engine: Roadman, TAMI RHINO-JUMP)

Aside from above classification according to power source, motorized skateboards are also categorized into "street boards" and "all-terrain boards" depending on the size and types of wheels mounted on the board.
If a powered skateboard has solid urethane wheels like those of a general skateboard without power source, it is fit for riding on areas covered with asphalt or paving block with an even surface. So, such a type of board is classified as a "street board." Some motorized skateboards are equipped with tube-tire type wheels to which air is injected, like the wheels of scooters. Those models tend to have more than 8" of tire diameter, a structure of a mountain board. So they can run not only on off-road and on lawn but also on compacted beach sand. Those boards are categorized as an "all-terrain board."
As "all-terrain boards" have large wheels, their size is big compared to "street boards."
-Picture Images (Zoom, 4Wheel-MBoard, TAMI RHINO-TURF)

Looked into further details, skateboards motorized by a gasoline engine can be classified into "a one-wheel drive type" and "a two-wheel drive type" according to their driving method. Although rare, there is also "a full-time four-wheel drive type."
As it is the case with cars, more driving wheels mean a better driving performance for motorized boards off-road or on rough road. But if it is on paved roads, even motorized skateboards with one powered wheel can guarantee successful traveling without wheels running idle, because a driving wheel has strong grip between the road surface and the wheel.

Motorized skateboards with two driving wheels show adequate driving force both on and off-road. But a differential system has to be applied because of the difference in driving distance between inner and outer wheels during cornering.
That the differential system is not applied while the two wheels are fixed at the ends of the driving axle may not create any difficulties for off-road driving and cornering. But, on paved roads, one wheel is forcefully rotated at the same speed with the other wheel during cornering, thereby causing unnatural turning.
In other words, the deck tilted during cornering is not well recovered when cornering should be done at the opposite side. That can be a danger.
For that reason, a "one-wheel drive skateboard" with light and smooth moves is much more favorable when you run only on paved roads and implement riding techniques of motorized skateboards.
Despite that, the running capability of two-wheel drive board on unpaved or rough road is another charm of motorized skateboard ridings. As a result, we have developed some TAMI models incorporated with "semi-differential system" that combines only the strengths of the two methods.
"RHINO-TURF" released in 2004 is a true "all-terrain board", "a model for both on and off road ridings" to which the semi-differential system is applied.
(Picture Images: Three different types of model)