A CPA is a public accountant (not someone who works doing his/her employer’s accounting, although larger companies may hire CPA’s as their controllers and CFO’s), and is licensed as a certified public accountant by the State Board of Public Accountancy where the exam is taken. In order to obtain the CPA license an accountant must pass a national examination and have the required accounting courses. A CPA generally must have 3 years of experience working for a certified public accounting firm.
By being certified, an accountant can perform audits on businesses financial statements. In addition, there are other financial statements that are not audited, Compilations and Reviews that CPA’s can perform. Each type of engagement has various requirements promulgated by the American Institute of Certified Public Accountants (AICPA).
Additionally, tax planning, both business and personal is an important part of many CPA’s repertoire. Most CPA’s prepare income tax returns for individuals, small closely held businesses, trusts, partnerships, limited liability companies as well as estates.
Some CPA’s also provide business consulting and negotiating, purchase and sales of a business, estate planning and financial services.
For in depth info on what a CPA does and how he/she becomes a CPA see either the wikipedia website for CPA’s, AICPA website or various State Boards of Accountancy.