A big wheel is a toy with three wheels with the front wheel bigger than the rear ones. Some people call it a tricycle (tri to mean three). And Big wheels come in three designs:
Upright Big Wheels: This big wheel has common features with the conventional tricycle, only that its front wheel is larger. As the name suggests, it is upright, making the user feel stable while using it. Kids who dislike lowriders will enjoy this one most.
Lowrider Big Wheels: When this big wheel design is mentioned, you'll hear terms like classic and leaning seats. This type of big wheel has the rider sitting low with his feet in front of him riding the pedals. This feature is connected to the front wheel.
Push-along big wheels: As the name suggests, these ones are designed to be pushed. They are made for small kids who cannot ride the real big wheel. They can either push the tricycle while standing or sitting on the low lying seat with their feet down to propel them wherever they need to go. Some parents use it to train their kids to walk around (it strengthens the legs).