Shares are traded through Brokers, there are no direct connectivity to stock market / exchange. Trade is the deal between buyer & seller on a price. Stock exchange is responsible for setllment if anything goes wrong. Buyers and sellers decides the stock price by competing. Order is nothing but share name, quantity, price. There are two types of order, Buy Order and Sell Order. When share price goes up, buying the share first time is known as Long position, Selling after the price goes up is known as Long Unwinding. Without having shares, if you sell the share it is known as Short position. Shares traded need to be bought on the same day before settlement is known as Short Covering.Buying stock now and selling few days later is known as Positional Trading. Buying and Selling shares within a day is known as Intraday. Stock trading is business provided returns are greater than risk. If risk is greater than risk than it is called as Gambling.