If you are for example, an employer, landlord, shop owner, business owner etc you have a duty of care to ensure the safety of your employees, tenants, customers, the public.
Part of this duty of care is ensuring the safety of any electrical appliances that your employees, tenants, customers etc use or are exposed to. As well as being the duty holder your Insurance requirements might also stipulate a similar requirement to make sure your equipment is regularly tested.
“PAT” stands for “Portable Appliance Test” and portable items might be eg- power tools, food mixers, electric kettles, lamps, TV’s and DVD players
All Extension leads, adapters, multi plugs, power cables etc are items that should be included in a PAT test.
Some items that are not so portable also fall within the scope of the test (eg vending machines, dishwashers, washing machines etc) ie they are not portable but are movable. Some parts of electrical equipment are outwith the scope of the PAT test like fixed wiring (behind walls and not movable) but in general if the appliance can be moved then it falls within the scope of PAT testing.