There are four main types of options:
1. Call options: These give the buyer the right, but not the obligation, to purchase an underlying asset at a predetermined price, known as the strike price, on or before a specific date.
2. Put options: These give the buyer the right, but not the obligation, to sell an underlying asset at a predetermined price, known as the strike price, on or before a specific date.
3. American options: These can be exercised by the buyer at any time before the expiration date.
4. European options: These can only be exercised by the buyer on the expiration date.
There are also other types of options, such as exotic options, binary options, and digital options, but these are less commonly traded and typically have more complex structures.