Goodwill is an intangible asset on the books of an enterprise/firm, often created as an effect of factors such as trustworthiness, brand image, profitability and value perceived by its customers and stakeholders. 

Goodwill is housed under assets in accounting for the firm but it is realised as money only when the firm is sold off. It is the value paid by the acquirer over and above the fair market value of the firm’s assets when being acquired.