Foreign Exchange Market

Spot Market: 
Where exchange of one currency for another currency being happened on the spot or within two Banking days.
Forward Market:
Where actual transaction or delivery of Foreign Currency to be happened at a future date of period as per today's agreement.
Future Market:
Where two parties agreed to buy or sell a fixed quantity of particular commodity, currency or security for delivery at a fixed date in the future at a fixed price. It obliged a definite purchase or sell and not an option to buy or sell. In these transactions small security deposit is required.
Option Market:
An option is a contract specifying the right to buy or sell (by the buyer of the contract) a standard amount o foreign exchange with in a specific date at a certain price. A call option confers the right to buy and a put option confers the right to sell. Buyer of the contract has the right not to buy or sell. If he lapses the deal he will loss only option money.