Auction A type of sale where customers take it in turns to offer higher and higher prices for something until no-one wants to pay more. Then the person who offered the highest price wins.

Borrow To get money from someone (a person, bank or building society) with the intention to pay them back later. You may be charged interest for borrowing money (see Interest). You normally need to be 18 to borrow from a bank and meet certain bank conditions.

Cash Coins or paper money that you can use to buy things in a shop or for services, such as a train ticket.

Contract A written agreement between people that shows what will be done, how much will be paid and the date it will be done by.

Debt Money owed to someone who has given you a loan. You can be in debt to a person, bank or financial services provider. Usually the longer you are in debt, the more interest you have to pay.

Income The amount of money you earn or receive.

Interest The fee that lenders charge when you borrow money. Some lenders offer interest-free loans. If you put your money in a bank or building society, they will usually pay interest to you.

Overdraft The bank or building society may allow you to borrow a certain amount of money if you have used all the money in your account. You will usually be charged for overdrawing money. To get an overdraft, you need to be over 18 and meet certain bank conditions.

Profit If you get more money when you sell something than it cost you to buy or make, the difference is called profit. The opposite of profit is loss, which is when you receive less money than it cost you to begin with.

Recommended retail price (RRP) A price that the company making a product (for example, a toy) thinks shops should sell the product to you for.

Savings account A bank or building society account that helps turn your savings into more money by paying you interest. These accounts usually pay you more interest than normal bank accounts, but you may not be able to withdraw money from the account without telling the bank or building society in advance – you should check with them if there are any restrictions on accessing your cash. Use your GoalSaver app to help you save and work out when you'll be ready to spend it!