By studying the internal controls an organizations strength and weakness can be revealed where internal controls are strong auditors would require testing the financial figures less. 

Adequate internal control will provide for extensive segregation of duties so that no one person handles a transaction from start to finish. 

The auditor will need to evaluate the effectiveness of the internal control mechanisms to determine the extent of the audit in any given assignment to achieve this a thorough knowledge and understanding of the business and the controls are necessary. 

Definitions:- In a study sponsored by the American Institute of certified public accountant the Institute of Internal Auditors and other bodies Internal controls have been defined as a process affected by the entity board of directors management and other 

personnel designed to provide reasonable assurance regarding the achievement of the following categories. 

On the other hand, the instituted of chartered Accountants (England & Wales) defined Internal control audit as not only internal check and internal audit but all systems of control both financial and otherwise established by management of an organization designed to ensure adequate production of the organization assets against unauthorized use, theft and fraudulent abuses. Internal audit is therefore part of internal controls and is the technique of internal control established to ensure that internal audit staff carry out their duty in order to guarantee smoothness of the operations, control and prevention of fraudulent activities and then ensure compliance with organization policies. Internal checks are a system where by no single person is allowed to initiate a transaction in an organization and conclude every aspect of it alone. This internal control is a process and a means to an end, not itself, it is not merely the policy document or manual. In other words, where these exist but not put into practice there is no internal control. 

Bearing in mind that internal control involves a systematic process of objective obtaining and evaluating evidence regarding assertions about economic action and events to ascertain the degree of correspondence between those assertions and established criteria and communicating the results to interested users. Internal control therefore is an accounting procedure or system designed to promote efficiency or ensure the implementation of a policy to safe guiding assets or avoid fraud. Fraud which is intentional deception resulting in Financial injury and loss to another person or persons which may results to corruption which is Lack of integrity or honesty especially susceptibility to bribery, use of position trust for dishonest gains. 

The term internal control denotes the systematic organization of accounting/clerical duties and routine procedures as such a way as to ensure that Fraud and irregularities are impossible without conclusion and that innocent mistakes are detected and corrected at early stage. 

This necessitates a sub-division of duties by means of which no one person is responsible for the entire work in connection with one transaction but at the same stages in its performance the work done by each person with that transaction comes under the supervision of at least one other person. 

The extent to which sub-division of duties is possible in practice depends on the size of the business concern there is a scope for internal check where several checks are employed although in a very small office the personal supervision of the proprietor is a strong deterant to irregularities.