You should really be asking what the difference is between a ukulele and a banjo-ukulele. The difference is essentially the same as between a guitar and a banjo. They both have 4 nylon strings and are tuned in the same way. One is made of wood and the other has a plastic or vellum head.

As for the Banjolele - that is the trade name of banjo-ukuleles made by the firm of "Alvin D Keech".

Apart from them burning longer, be very careful about leaving them in the back of the car unattended. A friend of mine did this and, on returning, found that someone had broken into the car and left him another one.
Ray