This is a very easy question according to some people and a very difficult one according to others. The majority of people in the UK will use the word lorry interchangeably with the word truck or as the Oxford English Dictionary describes it: “a large, heavy motor vehicle for transporting goods or troops; a truck”.
Yet some people argue that all lorries are trucks but not all trucks are lorries. They say that a truck is any type of vehicle that transports loads heavier than 3.5 tonnes and that a lorry is a truck with a self-contained unit for cargo and a cabin. Similarly, it is said that some trucks are a lot larger than a lorry.
On the other hand, some people argue that trucks are actually the smaller equivalent of lorries. We imagine they think more about pick-up trucks and vans when talking about trucks while lorries are the big cargo-carrying vehicles on the road.
Even about the origin there is not much agreement. According to the Oxford English Dictionary again, the word lorry comes from the given name ‘Laurie’ in 19th century England yet other sources claim the word comes from the Northern English word ‘to lurry’ which means ‘to lug, pull about or drag’.
In summary, we’re not 100% sure where a lorry stops and a truck begins but what we do know is that most British people use it as another word for a large vehicle carrying goods, a truck. And the Oxford English Dictionary seems to agree.