If you have an undergraduate tuition fee loan
If you take out a loan with the Student Loan Company to cover the cost of your education, then you will only start to repay your loan once you earn over £25,000 per year (for students who started from September 2012 onwards). And once you are earning over that threshold, the amount you pay back will increase in proportion with your earnings (9% of any money you earn over £25,000). For example, if you earn around £30,000 per year you would make repayments of about £37.50 a month - less than buying a daily coffee.
If for any reason your earnings go down, or you take some time out of work and therefore earn under £25,000 per year you stop paying back your loan. And after 30 years, any outstanding debt is written off. While the benefits of university stay with you for a lifetime, the cost is time-limited.