A stockbroker undergoes training to provide investment advice and recommendations. They follow companies and industries to compile information for clients. However, a stockbroker's primary role is to sell products, not provide unbiased advice. There are three basic types of stock orders a broker can place - market orders which execute at the best current price, limit orders which execute at a specified price, and stop orders which become market orders if a certain price is reached. Investors can also open cash or margin accounts, with margin accounts allowing borrowing to purchase stocks.