www.stockmarketways.com [ basic of options ]

LEVERAGE
OPTIONS typically cost only a fraction of the stock price. if you think abc stock currently at $ 49 per share, is going up in price , you can purchase 100 shares at a cost of $4900.if instead you buy 1 call option contract [1 contract represents 100 shares of stock normally you can cheked them how many contract in one lot and lot size NSE INDIA and COBE]  YOU might pay only $2 per share for a total of only $200 to participate in a upward price movement of abc stock.
analogously, if you think abc is going down in price you could short 100 shares but that creates a margin responsibility in your brokerage account, which can become costly if abc goes up. if instead you buy one put contract you might pay just $ 2 per share for a total of only $200 to participate in a downward movement of abc.

TIME LIMITATION
One reason options are cheap is that they are time limited. A long or short position involving stock can be held indefinitely ,but an options expires on a fixed date . The expiration date is typically the third friday  of the expiration months designated in the option contract .when you buy a option, you can selecct various expiration months, including the current month as well as other months going out possibly as far as two years.

PRICE MOVEMENT
As the stock price changes the option price also  changes  but a lesser amount. how closely the change in the option price matches the changes in the stock price depends on the reference price is designated in the option contract . this reference price is called the strike price.
When you decide to purchases an option, there will be several strike prices from which to make a selection. For most stocks the strike prices of its options are set at $5 increments within the broad trading range of the stock .
For some lower and medium priced stocks, strike prices are offered in increments of $2.50 whereas options on some high priced stocks only have strike price increments of $ 10.