Some mopeds are of a step-through type design, while others are step-over designs, having a motorcycle-like frame, including a backbone and a raised fuel tank, mounted directly between the saddle and the head tube. Some resemble motorized bicycles. Most are similar to a regular motorcycle, but with pedals and a crankset that may be used with or instead of motor drive. Although mopeds usually have two wheels, some jurisdictions classify low-powered three- or (rarely) four-wheeled vehicles as a moped.
The word moped was coined by the Swedish journalist Harald Nielsen in 1952, as a portmanteau of the Swedish words "motor" and "pedaler". The claimed derivation from the term motor-velocipede is incorrect. According to Douglas Harper, the Swedish terms originated from "(trampcykel med) mo(tor och) ped(aler)", which means "pedal cycle with engine and pedals" (the earliest versions had auxiliary pedals). Like some of the earliest two wheeled motorcycles, all mopeds were once equipped with bicycle pedals.
The term moped has now been applied by some regional governments to vehicles without pedals such as motor scooters, based on criteria of restricted engine displacement, speed, and/or power output. This is a misnomer, as they are no longer "mopeds" at all, and might instead be called a "noped" if they appear to look exactly like a typical moped, but no longer include pedals.
Other terms used for low-powered cycles include motorbicycle, motorized bicycle, motor-driven cycle, and goped (motorized inline skateboard with T-bar). The term noped is sometimes used for mopeds that do not have pedals.
The term "moped" now only applies to low-power (often super-economy) vehicles, but pedals were fitted to some early motorcycles, such as the pictured 1912 Douglas. Pedalling away from stationary was a great improvement over "run and jump" and light pedal assistance (LPA) was valuable for climbing hills. Better transmissions with wider ranges, better clutches and much better engine performance made pedals obsolete on most motorcycles by 1918 but the pedals on mopeds remained valuable for their original purposes as late as the 1990s.