To make comparisons between companies, sectors and markets a little easier, there are a number of mathematical models used. The most common and often the most helpful is the P/E ratio. The Price to Earnings ratio takes the share price and is divided by the earnings per share. It is possible to calculate this using past earnings, projected future earnings and with all sorts of moving averages ;-) Therefore, this is one number that it is vital for any investor to know and understand.
Trading platforms are portals through which users access and manage their trading accounts for their financial markets. This helps the users maintain their accounts. Generally, such platforms are offered by brokers in exchange of some fee or discounts on trade commissions. With the advent of the discount broking industry, several platforms are also available for free or rather, access to platforms is included in the brokerage you pay. These platforms can be used to conduct research, keep a track of various financial products you wish to trade in, place orders, store your past trade details as well as to authenticate users. Trading platforms have opened up the possibility of e-trading or online trading.