Finally, trading platforms may have specific requirements to qualify for their use. For example, day trading platforms may require that traders have at least $25,000 in equity in their accounts and be approved for margin trading, while options platforms may require approval to trade various types of options before being able to use the trading platform.
This is an excellent learning experience and one that is vital to the long-term profitability of anyone in the stock market. To get the real experience, purchase some graph paper and chart the stock price movements each day by hand. Learn to compare this with the overall movements of the equity market or index and a whole new world of investment and money will begin to open up to you!
For online platforms, websites give the user options and availability of the stock he wishes for, across all the platforms available. If he places an order, it gets stored in a database. After the confirmation of the trading account and payments, the order gets forwarded and the user gets his stock, in the form of money, transferred to his trading account.