Difference Between CPA and EA

CPA stands for Certifid Public Accountant and EA stands for Enrolled Agent. 

Enrolled Agent is the highest accreditation awarded to tax preparers.

Certified Public Accountant (CPA) is the title of qualified accountants in numerous countries in the English-speaking world. It is generally equivalent to the title of chartered accountant in other English-speaking countries. In the United States, the CPA is a license to provide accounting services to the public. It is awarded by each of the 50 states for practice in that state. Additionally, all states except Hawaii have passed mobility laws to allow CPAs from other states to practice in their state. State licensing requirements vary, but the minimum standard requirements include passing the Uniform Certified Public Accountant Examination, 150 semester units of college education, and one year of accounting related experience.
Source: https://www.wikipedia.org/

Enrolled Agent (or EA) is a tax advisor, who is a federally authorized tax practitioner empowered by the U.S. Department of the Treasury. Enrolled Agents represent taxpayers before the Internal Revenue Service (IRS) for tax issues that include audits, collections and appeals.

Enrolled Agent status is the highest credential awarded by the IRS. The EA credential is recognized across all 50 U.S. states. Attorneys and certified public accountants (CPAs) are licensed on a state by state basis and are also empowered by the Department of the Treasury to represent taxpayers before the IRS. According to the National Association of Enrolled Agents, there are approximately 53,000 practicing EAs in the United States.
Source: https://www.wikipedia.org/