Originally Posted by Reprobate
A moped, called 'brommer' here, is a motorcycle with 49.9cc engines or less. Like these:
The main difference is in the wheels.
A scooter can be a 'bromscooter' [49cc] or a motor scooter [50+ cc], but they have smaller wheels and a space between the seat and the handlebars where you can step through, like with Vespa:
So, basically, a motorcycle with a small displacement engine, less than 50 CC, is a moped.
A Vespa, or Vespa-clone, is a scooter, and can be a moped [<50CC] or a motor scooter [>50cc].
seems a terribly complicated answer, that doesn't really define 'moped' other than being a small motorcycle with big wheels.
I always thought a true Moped was a motor driven cycle that could also be propelled by turning a set of bicycle style pedals. Mo (motor) + Ped (Pedal)