It's been some years since law books had titles like "The Law of Master and Servant". Times change and we don't use those terms any more. But semantics are still important in the area of what in the US we'd call labor law: for example, what does it mean when someone is referred to being employed or self-employed? It's easy to think that a self-employed person pays their own tax and has no employment type rights. That is by no means the case and this confusion was apparent in some media reports of the Employment Appeal Tribunal Addison Lee decision issued last week. "Drivers held to be employees" was a typical headline. In fact, the drivers were held to be "workers" not employees. There is a significant difference in the consequences of being put into one or other of these categories. So what exactly is this difference?