Deposit accounts.
These are the normal bank / building society savings accounts which are used to hold cash you don't need at the moment and which pay a nominal rate of interest to you - usually once a year.
In basic terms, the longer you are prepared to leave your money alone, the better the rate of return you can expect to receive. It is the norm for these rates to fluctuate over the year as general rates of interest alter. Typical periods will include 30, 60 & 90 day notice accounts.
As well as these, sometimes "bonds" are available for periods of 1-5 years. These often promise either a fixed rate of return or a certain amount over & above the rate paid on certain other accounts in return for you investing over a reasonable period and giving up access to the money.
It is wise to keep some funds on "instant access" where you can take money out without having to give notice. This can be either by the use of a card that can be used in cash machines or the more traditional route of having a passbook. This records all of your transactions along with your signature and other details encoded for security purposes.
The "best buys" are often postal accounts. These are run centrally from a company's head office rather than through the normal network of branches. Some firms insist on being given notice for withdrawals, others provide cash cards so that money can be obtained swiftly whenever required.