The definition of audit can be stated like an evaluation of some particular system, person, organization, process, enterprise, product or process.  Audits are generally performed to know whether information is valid and reliable or not. Not only this but also it depicts the internal assessment of some information. The main purpose of audit is to find out some questions regarding the on going progress of some system, person etc.

At the first time audit is performed on something when it is under the testing period. Audit totally depends on practical constraints. Thus very efficiently it assures that a system, person, organization is free from any kind of material error. Statistical calculation sometime becomes very essential. In case of financial audit the statements are considered to be true when they are free from any kind of material misstatement. In this regard not only quantitative factors are considered, qualitative factors are also important.

The pillar of accounting is audit. Previously audit was used in some specific cases like the measurement of entire profit of a system or organization. But now days it has got some new dimension and has spread up to almost every calculation in a system. Some new features are included and it has become indispensable for calculating security risks, system performance. Environmental performance measurement is also included in the features of audit.

People are getting interested in learning the pros and cons of audit. Now professionals are available in different section of audit i.e. security auditor, environmental auditor, IS auditor etc. In financial accounting audit is represented as the fairness among the statements provided by the management. The auditors are there to generate an audit report. This audit report must match with the report created by the governing bodies of the organization. If these two reports results in same the product or information is totally true and it can assure customers to a great deal.     

Quality audit verifies effectiveness of a management system. ISO 9001 certification assures the quality of the audit. Quality audit is there not only to assess the quality of implemented processes but also judges the effectiveness of achieving certain target level. Sometimes it becomes a handy tool for measuring the overall progress of a particular organization. It also highlights the areas need to be improved. So other departments of organizations share the information and can enhance the overall performance of the organization.

In United States audit is performed under the guidance of public Company Accounting Oversight Board. This kind of audit is known as Integral audit. In this type of audit auditors have some extra responsibilities. They are invited for expressing their opinions in front of the management for the overall assessment of the organization.

Basically there are two types of auditors, internal auditors and external auditors. Internal auditors are responsible for providing reports directly to the management or the board of directors. They are directly related to an organization. But external auditors are not directly related to a company. They are appointed by some auditing firms. They are hired as per requirement.