A share, also known as a stock or a equity, represents a unit of ownership in a company. Companies issue shares to raise capital, and the price of a share is determined by supply and demand on the stock market. When you own shares of a company, you are entitled to a profit sharing,& decision making of a company' run (though the extent of your influence will depend on the number of shares you own).
There are different types of shares that a company can issue, such as common shares and preferred shares. Common shareholders have the right to vote at shareholder meetings and receive dividends, if the company declares them. Preferred shareholders have the right to receive dividends before common shareholders, but do not usually have voting rights.
Companies may issue shares for a variety of reasons, such as to raise capital to fund operations and growth, to pay off debt, to finance acquisitions, or to reward employees through stock-based compensation. By selling shares, a company can raise money without taking on additional debt. This can be especially appealing to companies that want to avoid the costs and restrictions associated with borrowing.