In corporate finance, a listing refers to the company's shares being on the list (or board) of stock that are officially traded on a stock exchange. Some stock exchanges allow shares of a foreign company to be listed and may allow dual listing, subject to conditions.
Normally the issuing company is the one that applies for a listing but in some countries an exchange can list a company, for instance because its stock is already being traded via informal channels.
Stocks whose market value and/or turnover fall below critical levels may be delisted by the exchange. Delisting often arises from a merger or takeover, or the company going private.