I am about to open up a stock market account with TradeKing but I have no idea about investing. I was looking at the rates of trading and it said that its was $4.95 per trade and $4.95 plus .65 for a stock option contract. What is a stock option? And how is it different from a regular stock. I tried to look up the definition but all the answers are so complicated. Can someone in plain english please explain. Thank you so much!