Broadly speaking, there are 2 types of Equity Options:

1. A "Call" option gives the buyer the right, but not the obligation, to buy the underlying shares at a pre-determined price.

2. A "Put" option gives the buyer the right but not the obligation to sell the underlying share at a pre-determined price.

In both cases, the buyer of the option pays the option seller a fee (called premium). Options are not suitable for all investors, as they carry significant risks. They are recommended only for investors with appropriate risk appetite. 

Selling options generally entail considerably higher risks, when compared with purchasing options. The option seller may sustain a loss well in excess of the option premium amount received if the share price moves in the opposite direction of what was anticipated