Companies and shareholders: introduction: issues of shares in public companies
Shares in private companies cannot be offered for sale to the general public and are generally issued to the founders of the company. For public companies, there are two categories of share issue, primary and secondary.
A primary issue of shares is an issue that takes place when a company is first admitted to a stock exchange. Sometimes this is known as the Initial Public Offering (IPO) or offer for sale (STSM071080).