There are 2 kinds of options: calls and puts. Calls allow you the option to buy 100 of stock at a certain price any time before the option expires. Puts are the opposite, they allow you the option to sell 100 stocks for a certain price any time before they expire.
Note, that I said "option", you're not obliged to sell or buy stocks; however, if you let the option expire you lose the money you spent on the option.
I haven't bought options so I can't tell you exactly what the price of an option is relative to a share (some posters say 100:1), but it would have to be much less than the price of a share to be worth it. Since to make money from an option, the stock has to move enough to pay for the price of the option and if the option is too expensive, the stock price would have to move a lot.