Hi Esther. One major difference between public and private accounting is that public firms offer multiple services to a variety of business clients in a variety of industries. These services are generally assurance (audit) or compliance (tax). The SEC dictates all publicly traded companies to report audited financials in accordance to GAAP. The Big 4 accounting firms often score publicly traded companies as their clients. Working for the big 4 is often challenging because of the complex nature of the job and you will be working long hours. Private accounting means compiling a company's financial statements or whatever necessary, depending on the size. This company can be a private company (mom & pop shop) or a publicly traded company (Fortune 500). To be an accountant for a publicly traded company or auditing one, you will need to be a licensed CPA.