We don't mean by this that some people have different life-styles from others, live in different areas or have snobbish attitudes and different accents.
Class is the material reality on which our society and all others in the world today are based.
Or else they sweep streets, dig coal or scrub floors for the 'public sector' so that the system can keep going, with the rich making as much profit as possible and the needs of the poor supplied at the lowest possible cost. This is the working class, and without its labour the lights would go out, food and water would be cut off, communications would break down and society would cease to function. At the top, a tiny minority of people own most of the wealth and exercise most of the control. They decide when factories will close, when prices will go up, when capital will be moved around so as to browbeat governments into doing what they want. Some belong to families who have held wealth and power for generations, others insist that they have 'worked their way up' and are 'still very working class'.