Credit card limits
Some cards are aimed at people with a poor credit history and have a low limit of £200 or so. Often these cards have a high interest rate, but if you pay them back on time, they can be a good way to boost your credit rating by showing other creditors that you can be trusted.
Other cards have a much higher limit which can go into the thousands. Whether you have a low or high credit limit, it's very easy to run up affordable debts which will take a long time to pay back.
Sometimes your card provider will offer to increase your credit limit, especially if you have a good history of payments. You should think very carefully before agreeing to an increase in your credit limit, and refuse the increase if you don't need it. Some people like a higher limit 'just in case', but there's always the temptation to keep spending and run up a debt you eventually can't afford to pay back.