Goodwill is an accounting concept meaning the value of an entity over and above the value of its assets. The term was originally used in accounting to express the intangible but quantifiable "prudent value" of an ongoing business beyond its assets, resulting perhaps because the reputation the firm enjoyed with its clients.
Goodwill in financial statement

Financial statement

A financial statement is a formal record of the financial activities of a business, person, or other entity. In British English—including United Kingdom company law—a financial statement is often referred to as an account, although the term financial statement is also used, particularly by...

s arises when a company is purchased for more than the fair value

Fair value

Fair value, also called fair price , is a concept used in accounting and economics, defined as a rational and unbiased estimate of the potential market price of a good, service, or asset, taking into account such objective factors as:* acquisition/production/distribution costs, replacement costs,...

 of the identifiable net assets of the company.