The six main types of motorcycles are generally recognized as standard, cruiser, touring, sports, off-road, and dual-purpose. Sport touring is sometimes recognized as a seventh category or integrated with the touring category.

Although there are many names and systems for classifying types of motorcycles based on their characteristics and usage, there are generally six categories recognized by most motorcycle manufacturers and organizations.

Strong distinctions are usually made between the six main types of motorcycles and other motorcycles. Scooter, moped, underbone, miniature, pocket, electric, and three-wheeled motorcycles are generally excluded from the main categories but other classification schemes may include these as types of motorcycles.

There is no universal system for classifying all types of motorcycles. There are strict classification systems enforced by competitive motorcycle sport sanctioning bodies, or legal definitions of a motorcycle established by certain legal jurisdictions for motorcycle registration, emissions, road traffic safety rules or motorcyclist licensing. There are also informal classifications or nicknames used by manufacturers, riders, and the motorcycling media. Some experts do not recognize sub-types, like naked bike, that "purport to be classified" outside the six usual classes, because they fit within one of the main types and are recognizable only by cosmetic changes.

Street motorcycles are motorcycles designed for being ridden on paved roads. They have smooth tires with tread patterns and engines generally in the 125 cc (7.6 cu in) and over range. Typically, street motorcycles are capable of speeds up to 100 mph (160 km/h), and many of speeds in excess of 125 mph (201 km/h). Street motorcycles powered by electric motors are becoming more common, with firms like Harley-Davidson entering the market.
Without quoting directly from the text give me a summary of the different types of motorcycles.
Motorcycles are 2 wheeled vehicles powered by an internal combustion engine generally made for a single rider.  Although there are many styles of motorcycles, they are loosely organized into 6 main categories.  These categories most closely align to the intended use of the vehicle.  There is your standard motorcycle, your more relaxed cruising motorcycle, the larger capacity and longer haul touring cycle, a racing more sportier sports cycle and then you have a off-road motorcycle often known as a dirtbike and lastly a dual-sport which is a motorcycle that can go both on and offroad.