The British have their own vocabulary: What we would call a dormitory, they call a House. In most schools, you join a House of about 50 or 60 when you are 13 and stay there for five years: each House, therefore, will have about 10 pupils (as students are called) in each year. Some schools, however, have separate Houses for the Sixth Form, often with cooking facilities where you can make your own breakfast or snacks.
Each House has a Housemaster or Housemistress and usually one or more Tutors (at other hours known as Masters, what we would call teachers). The Housemaster or Housemistress acts as your surrogate parents; the Tutor, along with keeping track of your academic work, gives you someone to talk to about anything at all- your problem with the girl down the hall, how to get involved in community service, the intricacies of the latest political crisis, a sonnet by Shakespeare you decided to read on your own.
Much of the responsibility of running the House falls to the pupils, to the Head of House and Prefects, a small group of senior boys or girls. Their main job, and yours as a member of the Sixth Form (or as a Prefect should you be appointed one by the Housemaster during the year), is to set a good example for the younger pupils in the House. Yes, there are rules: drugs and smoking are forbidden, the use of alcohol confined usually to the school pub (if you are over 18). If the school is coeducational, certain visitation rules will apply.
And there are traditions, often quaint and sometimes seemingly pointless, but followed nonetheless. But far from being annoying, these traditions are one of the reasons you decided to go to Britain in the first place: to see a different culture from the inside, to learn by immersing yourself completely in a new way of life.