Look around you. What do you see? A computer in front of you? A desk? A classroom? A playground, a park perhaps? Trees, traffic lights? A teacher? These things - or people - don't just appear out of nowhere.
They are all administered by government - local and national.
And they are not free. Computers and desks need to be bought, roads need to be mended, playgrounds and parks need to be looked after, traffic lights need to work so there aren't big pileups, teachers need to be paid - whether you want them or not!
These things are called public services. They are things that everyone benefits from. Other public services include the health system, the armed forces, the environment and benefits if you are unemployed, homeless or need to stay at home to look after a relative.
Not everyone in the country will need to go to the doctor or have to claim housing benefit, but the whole society benefits by a healthy population and one that has somewhere to live, so we all take on the responsibility to pay for these things.