A share means ownership in a company and is the smallest unit of ownership a company can offer. A company that is listed on the Stock Exchange can issue shares to the public.
In the Stock Market (Stock Exchange), buyers and sellers exchange shares. This is called Share Trading. When a buyer agrees to purchase shares from a seller at an agreed-upon price, the transaction occurs. The general laws of supply and demand also govern the prices of shares. When there is more demand than supply, the price of the shares (stock) goes up, and the opposite occurs when there is more supply than demand.
In India, trading 'Shares' are also known as trading 'Cash' and is also known as trading Equity. All three are one and the same.