The term Audit is derived from the Latin term 'audire,' which means to hear. In early days, an auditor used to listen to the accounts read over by an accountant in order to check them. Auditing is as old as accounting. It was in use in all ancient countries such as Mesopotamia, Greece, Egypt, Rome, U.K. and India. The Vedas contain reference to accounts and auditing. Arthasashtra by Kautilya detailed rules for accounting and auditing of public finances.
If you are interested in dissecting the inner workings of almost any aspect of a company, a career as an auditor may be for you. From poring over financial statements and expense reports to ensuring compliance with government regulations, auditing offers a wide variety of potential career opportunities.
The original objective of auditing was to detect and prevent errors and frauds.
Audit is the examination or inspection of various books of accounts by an auditor followed by physical checking of inventory to make sure that all departments are following documented system of recording transactions. It is done to ascertain the accuracy of financial statements provided by the organisation. 
Economic decisions in every society must be based upon the information available at the time the decision is made. For example, the decision of a bank to make a loan to a business is based upon previous financial relationships with that business, the financial condition of the company as reflected by its financial statements and other factors. If decisions are to be consistent with the intention of the decision makers, the information used in the decision process must be reliable.
A common way to obtain such reliable information is to have some type of verification (audit) performed by independent persons. The audited information is then used in the decision-making process on the assumption that it is reasonably complete, accurate and unbiased.
Audit can be done internally by employees or heads of a department and externally by an outside firm or an independent auditor. The idea is to check and verify the accounts by an independent authority to ensure that all books of accounts are done in a fair manner and there is no misrepresentation or fraud that is being conducted.
 All the public listed firms must get their accounts audited by an independent auditor before they declare their results for any quarter.  Who can perform an audit? In India, chartered accountants from ICAI or The Institute of Chartered Accountants of India can do independent audits of any organisation.
Auditing is a complex career, involving many different job responsibilities:
*Auditing involves the review, analysis and evaluation of processes, products, services, systems, organizations and employees.
*Auditors assess the accuracy, validity, reliability, verifiability and timeliness of organizational information, as well as the sources and processes by which that information is produced. This is an important role, because management and external parties thereby obtain an accurate assessment of the organization under their stewardship.
*Auditors also inspect an organization's internal controls and the extent to which these controls manage an organization's risk exposures. Internal controls help prevent the theft of a company's assets and, if properly designed and executed, prevent data manipulation by employees.
*Auditors ensure that checks are in place to help with the effectiveness of financial and operational reporting. They also make sure that controls are in place to protect an organization's assets.
Types of Auditors
Internal Auditors- Internal Auditors are employed by individual corporations, government bodies or other entities. Internal auditors work for the organisation they audit. Their job is to make sure the organization runs efficiently and effectively. They perform financial, internal control, and compliance audits for the employer. Internal auditors verify the effectiveness of their organization's internal controls and check for mismanagement, waste, or fraud. Sometimes they also help the external auditors with the financial statement audit.
External Auditors- External Auditors are also known as Independent Auditors or Professional accountants in public practice. An External Auditor audits financial statements for companies, and other organizations. They also give advice in preparing income tax returns and provides guidance in matters concerning compensation and healthcare benefits for employees. They are usually self-employed. 
Government Auditors- Government Auditors work in the public sector, they are employed by local and state governments. Government auditors maintain and examine the records of government agencies, and audit private businesses and individuals whose activities are subject to government regulations or taxation. Government auditors main task is to act as assurance on compliance audit and operational audit.
Forensic Auditors- Auditors could specialise in Forensic accounting. Forensic auditors often discover information that's used as litigation support. Forensic auditors mission is to detect, investigate and deter fraud and white-collar crimes. Forensic auditors are often employees of corporations, audit firms, government agencies and investigative and consulting services firms.
Eligibility
To become an auditor, one must have at least a bachelor's degree in Commerce, or in Accounting. Some employers may prefer those with master's degree in accounting. MBA with specialization in finance can also be a right subject choice. Courses in economics, commerce and statistics are also helpful.
Some universities conduct specialized courses in auditing. Along with subject specialization, computer literacy is also essential. One must take a course in computer accounting software's such as Tally or some other related diplomas. One can further take up more advanced courses like ICWA, CA, Company Secretaryship or etc.
Courses Available
There are plenty of courses are available in the field of Auditing & Taxation. In India,  universities offer courses in these fields from diploma to master's level. Some most sought courses in the field of Auditing & Taxation are mentioned below:
Diploma Courses
*Diploma in Auditing
*Diploma in Accounting & Auditing
*IRCA (Investment Information & Credit Rating Agency) Certified Course
*Advanced Executive Program in Cyber Security, Audit & Compliance
*Diploma in Taxation
*Diploma in Tax & Company Law
Skills Required
*Auditors should possess a strong ethical framework and report on issues (or anticipated issues) as they come across them.
*Good communication skills allow auditors to have a rapport with a variety of employees, managers, directors and external parties. As auditors establish good rapport with a variety of individuals, however, they should keep in mind the objectives of the audit (for instance, the reliability, verifiability, accuracy and timeliness of information), as they can often be tempted to not report on issues discovered.
*Strong interpersonal skills are important, due to the variety of informational requests - and often, resistance to those requests - required from a variety of sources. Strong and/or ambitious types may attempt to dissuade auditors from revealing embarrassing findings.
*Auditors need to be team players. As the scope of the audit can be large, it is beneficial to help in other areas of an audit when resource constraints warrant it.
*In this era of digital technologies, auditors need to be good with numbers as well as have the skills to optimise the potential of new technologies and move beyond traditional internal audit methodologies. Therefore skills in IT and data mining, and risk assessment are important for those getting into this field. 
*Finally, "professional skepticism" is an important trait to have, especially when reviewing a company's internal controls. One needs to assess how perpetrators of fraud can beat a company's controls, and auditors need to design and implement a system that can effectively protect the organization's assets.
Scope
With the growth in the economy and the number of business concerns boosting day by day, demand for auditors are increasing to ensure the credibility of the financial accounting data and financial statements in the private sector as well as public sector companies.
 One should not pursue a career in auditing merely because it is a lucrative filed, he/she must really love working with numbers and have an aptitude for mathematics. Companies registered under Companies Act are required to get audited annually. This has also made auditing an evergreen career field.
Rapidly changing technology and new software packages have made the work of auditors much easier. Record keeping and data management which was a tedious job earlier, has now become trouble free. Auditors typically can take advantage of career mobility, meaning they can switch careers between internal auditing and public accounting or from management accounting to internal auditing.  Internal auditors also learn the skills needed to become upper-level managers through their work, reviewing internal controls of business units.
In the beginning, most of the auditors work under the supervision of an established auditor. After gaining experience they can work independently.
A qualified auditor has the option of joining Government Service, Public Sector undertakings or taking up a lucrative assignment in the private sector  or corporate sector .  Some auditors work as teaching staff in colleges or universities. Auditing professionals may be self-employed and serve the needs of individual clients i.e. Auditing professionals are required in virtually every company, non-profit organization and government agency. Those employed in large firms are in part responsible for an organization's financial health. Nonprofit organizations are also very much reliant on auditors for continued solvency.
In India, auditors have many career opportunities such as
*Internal auditors
*External auditors
*Government auditors
*Forensic auditors
In manufacturing sector, insurance companies, banking sector, pecuniary institutions, corporate, financial firms, government service, public sector, teaching staff, non-profit organization and government agency etc. Many auditors carry out their private practice.
Indian Audit and Accounts Service
(IA & AS) is an Indian Central Government service, free of control from any executive authority, under the Comptroller and Auditor General of India. The officers of the Indian Audit and Accounts Service serve in an audit managerial capacity, in the Indian Audit and Accounts Department. IA & AS is responsible for auditing the accounts of the Union and State Governments and Public Sector Organizations, and for maintaining the accounts of State governments. It’s role is somewhat similar to the US GAO and National Audit Office (United Kingdom).
The service can be divided into officers looking after accounting and audit issues pertaining to the Union government and the State governments, and those manning the Department's Headquarters. The state accounts and audit offices are headed by Accountants General or Principal Accountants General. They are functionally equivalent; only the designations vary. The Deputy CAGs are the highest-ranked officers in the service.
After training, the Officer Trainees are posted as Assistant Accountant General Assistant Directors a Junior Grade Group A later promoted to Deputy Accountants General (DAsG) or Deputy Directors (DDs) a Senior time scale. Subsequent to their promotion, they become Senior Deputy Accountants General (Sr.DAsG) or Directors. All officers below the rank of AG/PD are also called Group Officers as they are generally in charge of a group in the office.
Institutes
*The Institute of Chartered Accountant of India (ICAI)- www. icai.org - offers certificate course in Internal Audit
*Institute of Internal Auditors (IIA)-www.iiaindia.org 
*The Institute of Internal Auditors gives Certified Internal Auditor (CIA) designation and ISACA provides Certified Information Systems Auditor (CISA) certification, respectively. CISA qualified Auditors have been recognized as qualified to conduct Systems Audit by Reserve Bank of India (RBI), Ministry of Information Technology (MIT), National Stock Exchange, Comptroller and Auditor General of India (C&AG).
Top Corporate Firms hiring Auditors:
*Deloitte
*Price Water House Coopers
*Ernst & Young
*KPMG
Auditing is a growing field, thanks to stricter government regulations, and offers a surprising variety of job responsibilities for those inclined to deal with the details of a company's operations. If liaisining with company management and regulating a variety of business and financial processes appeal to you, consider an in-demand career as an Auditor.