The most general definition of audit is “an official examination and verification of accounts and records, esp. of financial accounts”. Other than this audit is “a report or statement reflecting an audit; a final statement of account.”
In another definition, an audit is “an independent review and examination of records and activities to assess the adequacy of system controls, to ensure compliance with established policies, operational procedures, and /or evidence based standards of care and to recommend, where necessary changes in controls, policies, or procedures to ensure those standards are met”.
Audits are performed to ascertain the validity and reliability of information, and also provide an assessment of a system's internal control. Auditing is therefore a part of some quality control certifications such as ISO 9000. An audit is based on random sampling and is not an assurance that audit statements are free from error. However the goal is to minimize any error, hence making information valid and reliable.
Traditionally audits were mainly associated with gaining information about financial systems and the financial records of a company or a business (see financial audit). However recently auditing has begun to include other information about the system, such as information about environmental performance. As a result there are now professions that conduct environmental audits.
In financial accounting, an audit is an independent assessment of the fairness by which a company's financial statements are presented by its management. It is performed by competent, independent and objective person or persons, known as auditors or accountants, who then issue a report on the results of the audit.
When we gather all of the information from the above statements, audit:
· Must be applied to the financial information of a company during a certain period or to the general company processes.
· Is a process
· Based on gathering proofs and evaluation mentality
· Must be done by the experienced auditors
· Must be finalized by a audit report
The earliest surviving mention of a public official charged with auditing government expenditure is a reference to the auditor of the exchequer in England in 1314. However, audits are somehow accepted to have been performed at least since the fifteenth century. The exact origin of audits of financial reports is in dispute, but is known that as early as the fifteenth century auditors were called on to ensure the absence of fraud in the records kept by stewards of wealthy household estates in
under the ruling of Edward IV. England
The Auditors of the advance payments from treasury were established under Queen Elizabeth I in 1559 with formal responsibility for auditing Exchequer payments. This system gradually became obsolete and in 1780, Commissioners for Auditing the Public Accounts were appointed by statute. From 1834, the Commissioners worked in tandem with the Comptroller of the Exchequer, who was charged with controlling the issue of funds to the government.
The American accounting profession developed rapidly after World War I continued misunderstanding of the independent auditor's function was so widespread that in 1917 the Federal Reserve Board published in the Federal Reserve Bulletin a reprint of a document prepared by the American Institute of Accountants - which became the American Institute of Certified Public Accountants (AICPA) in 1957 - ostensibly dealing with uniform accounting, but in reality a treatise on how to audit a balance sheet. This
technical pronouncement was the first of many to be issued by the American profession throughout the twentieth century. United States
, prior to the 1930s, corporations were required neither to submit annual reports to government agencies or shareholders nor to have such reports audited. In the United States, the Securities Exchange Act of 1934 required all publicly traded companies to disclose certain financial information, and that financial information be audited. The establishment of the Securities and Exchange Commission (SEC) created a body to enforce the audit requirements. US
In the United States, the SEC has generally deferred to the accounting industry (acting through various organizations throughout the years) as to the accounting standards for financial reporting, and the U.S. Congress has deferred to the SEC. SEC is concerned primarily with promoting the disclosure of important market-related information, maintaining fair dealing, and protecting against fraud. This is also typically the case in other developed economies. In the
, auditing guidelines are set by the institutes (including ACCA, ICAEW, ICAS and ICAI) of which auditing firms and individual auditors are members. UK
Accordingly, financial auditing standards and methods have tended to change significantly only after auditing failures. The most recent and familiar case is that of Enron. The company succeeded in hiding some important facts, such as off-book liabilities, from banks and shareholders. Eventually, Enron filed for bankruptcy, and (as of 2006) is in the process of being dissolved. One result of this scandal was that Arthur Andersen, then one of the five largest accountancy firms worldwide, lost their ability to audit public companies, essentially killing off the firm. 
During much of the current century, certified public accountants (CPA) drafted their reports with little formal guidance. Common report language is so well developed today that audit reporting is no longer a writing exercise; it is a decision process.
As the time passes, the organizations got bigger and the complexity in these companies have increased. When we come to 1990s the industrial revolution was approximately 50 years old and industrial companies had expanded greatly in size. It was widely believed that the auditor's opinion was a guaranty of the accuracy of financial statements.
 Dictionary.com, “Audit”, http://dictionary.reference.com/browse/audit
 Auckland District Health Board, “Audit”, http://www.adhb.govt.nz/ResearchOffice/FAQ/faqs.htm#Audit
 Wikipedia, “Audit”, http://en.wikipedia.org/wiki/Audit
 Wikipedia, Ibid.
 Wikipedia, Ibid.
 Gözde Çekiç, “Hile ve Hile Denetimi”, Master Thesis,
, 2003, p. 3. Marmara University
 E.F.Jacobs, The Fifteenth Century, 1399-1485,
England, , 1961, p. 605. Oxford
 National Audit Office, “About Us: The History of the National Audit Office”, http://www.nao.org.uk/about/history.htm
 Securities and Exchange Commission, “Introduction”, http://www.sec.gov/about/whatwedo.shtml#create
 Securities and Exchange Commission, Ibid.
 Wikipedia, Ibid.