The AER - Annual Equivalent Rate - is a notional rate that's generally quoted on interest paid on savings and investments. It purports to demonstrate what your interest return would be if the interest was compounded and paid annually instead of monthly (or any other period). If an account pays interest more than once a year, say, for example, monthly or quarterly, then the AER is calculated by adding each interest payment to the deposit and then calculating the next interest payment, compounding the interest. Thus, on accounts where interest is paid quarterly, the AER will be slightly higher than the quoted gross rate because of the compound interest earned on the interest paid during the year.

Affinity cards operate like ordinary credit cards. However, they will be linked to a particular cause, which may or may not be charitable. Some charities offer credit cards (the schemes are run by card issuers on the charities' behalf) that make small percentage payments towards charity funds each time you use the card. There may also be a donation to the cause when you take the card out.

Annual percentage rate is required by law to be quoted by every firm involved in the business of advancing credit or lending money. The annual percentage rate be only one of a number of interest rates you may see quoted. It is also likely to be the highest of them. Personal loans, credit cards, mortgages and overdrafts may all be quoted at introductory rates of interest that sound enticingly cheap. However, what the introductory rates fail to include are any arrangement fees you may be charged for loans and they also won't immediately reflect any higher rate of interest that your borrowings will ultimately revert to.

Applied or nominal interest rate is the rate of interest which the lender uses to calculate the amount you actually owe them. The applied or nominal interest rate will not be the same as the APR as it does not include all charges. Hence it will be lower.

Balance Transfer. The credit card market-place is highly competitive. You may well find cards in the market that offer rates that are significantly lower than your existing credit card. Indeed, there are several credit cards available that promote interest free periods as introductory offers.

Bank interest rates vary according to a number of reasons. Banks change the rates of interest they offer to customers for two basic reasons. When the Bank of England's Monetary Policy Committee changes base rate, bank interest rates will usually, though not always, be changed to reflect the increase or decrease in base rate. However, bank interest rates, because they reflect the products that the banks are trying to market to consumers, may also be changed to reflect the product mix that a particular bank is trying to promote.

Car purchase. When you buy a car, you can pay for it in one of several ways: Pay cash - the best and 'cleanest' option. Not only will you be avoiding added debt, you'll be in the best position to negotiate a discount. Hire Purchase (HP) - you pay a deposit, perhaps between 10% and 40% and then pay off the debt plus interest in (usually monthly or quarterly) instalments. The asset (car) is not legally yours until the last payment is made. HP is sometimes called 'conditional sale'. Bank loan - you arrange a personal loan from a bank/ building society or other lender and use it to pay for the purchase. Unlike HP, from 'day one' the asset is yours. From then on, you just need to clear the loan making repayments and interest regularly (usually monthly or quarterly). Unlike HP, you don't need a deposit.

Cashback credit cards offer a straightforward cash reward for using them. These loyalty schemes return a percentage of your spending to you in the form of a cash rebate. The exact percentage on offer varies and most cash back credit cards tempt potential users with an introductory period offering a higher percentage return.

Cash cards are plastic cards, issued typically by banks and building societies and used for withdrawing cash from Automatic Teller Machines (ATMs) - also known as hole in the wall machines.

Cash machines are often referred to as 'cash dispensers' or 'hole in the wall machines'. Cash machines are a cross between a cash till and a computer, which enable users to access their bank accounts and carry out transactions such as withdrawing cash.