An MOT is a test that is required every year on your vehicle once the vehicle is 3 years old.
During an MOT numerous checks are carried out on the safety aspects of your vehicle, once checked and passed an electronic certificate is issued and registered on the government website and various databases used by law enforcement.
Driving your vehicle on a public highway without an MOT is an offence and could lead to your vehicle being ceased and fines of up to £1,000.