Answer by Peter Baskerville:
Here are some visuals to add to the excellent answers already given. Accounting is no different to any other system which has inputs, processes and outputs.
- The inputs in accounting are the financial transactions: events that have a monetary impact on an entity's financial position
- The processes in accounting include the double-entry bookkeeping: processing the fact that every transaction has will impact on at least two ledger accounts and that the debits will equal the credits for every entry.
- The outputs in accounting are the financial statements: summarising the financial activities and reporting on the financial performance and financial position of the enterprise.
This basic systems process can be broken down further into steps:
- Financial Transaction – events that have a monetary impact on an entity's financial position
- Source Document – original record containing the details to substantiate a transaction entered in an accounting system.
- Accounts classified – data on the source document is classified by account type
- Journals – Debit & Credit – the books of original entry where each financial transaction is recorded on a date and time basis and where the debits equal the credits for each transaction. (Separate sales and purchases journals may be kept to record the details of the individual debtors and creditors respectively)
- Posted – the process of transferring date/time entries from the journal to the account groups and types in the ledger.
- Ledger Accounts – contain the balances of all the accounts relating to a company's assets, liabilities, owners' equity, revenue, and expenses. (Separate debtors and creditors accounts may be kept to maintain the money owed by individual debtors and the money owed to individual creditors) Note: These subsidiary ledgers must be reconciled with the control account in the general ledger before financial reports can be prepared.
- Trial Balance (debit=credit) – is designed to check the accuracy of the general ledger and ensure that all postings to the ledger observed the rules of double-entry bookkeeping.
- Adjusted Trial Balance – is prepared after adjusting entries are made and posted. Recording adjustments relating to writing off bad debts, calculating depreciation and recognising prepaid expenses and unearned income.
- Financial Statements – summarising the financial activities and reporting on the financial performance and financial position of the enterprise.
After the financial statements are completed and distributed, post closing entries are journalised and a post closing trial balance is prepared in preparation for the next accounting period.