Stock trading is done in stock exchanges through the registered brokers. SEBI is a regulatory body for the stock exchanges in india. Stock trading should be done as a business not as gambling. The risk/reward ratio should be known. Stock trading is done by analyzing charts and drawing a trade plan which indicate the entry point, target, stoploss and quantity of stock to trade with. Stock trading is preferred mode of investment due to is high returns. It also highly risky. Trading could be long term (weekly, monthly, years together) they are usually investors. Intraday trading is trading done within a day.