In order to produce a balance sheet or an income statement it is necessary to have a systematic method of recording all the activities or events that have an effect on the financial measurements (A, L, P, I and E) described above. Traditionally these events were entered by hand into a set of books or accounts. More recently it has become common practice to enter these into a computer accounting system. Each entry is referred to as an entry and the practice of maintaining these entries in the accounts is referred to as bookkeeping. The act of placing a particular entry into an account is known as posting. The total of all the entries in an account is known as the balance of that account. The accounts themselves are referred to collectively as the general ledger or sometimes just the ledger.