What is auditing and how does it differ from accounting?

What is auditing and how does it differ from accounting?
Accountants prepare financial statements. Auditors review the work of accountants and render an opinion on the accountants work. Larger companies generally employ their own accountants and hire an auditing firm to review the work of their in-house accountants.There are four, very large, international auditing firms that are known as the "big-four": PricewaterhouseCoopers Deloitte Touche Thomatsu Ernst&Young KPMGThis group was once known as the "Big Eight", and was reduced to the "Big Five" by a series of mergers. Following the Enron scandal in 2002, the Big Five became the Big Four after the near-demise of Arthur-Andersen, who served as Enron's auditor.