An option in finance is the right to buy or sell an asset at a certain price at or untill a certain time in the future. On the Deribit platform it is possible to trade options on Bitcoin.
The option contracts that can be traded on the deribit platform are European style cash settled options. This means that options can only be made effective at the moment of expiration, and thus its not possible to exercise an option before its expiration. Instead of physical delivery of Bitcoin, at expiration (btc) cash settlement will take place.
The options are priced in BTC, but you can also see the relevant price in USD, using the latest index price to determine the price in USD. Also the platform shows you the Implied Volatility of the options price.
A BTC call option is the right to buy a bitcoin at a certain price, and a put option is the right to sell a bitcoin at a certain price.
Examples:
You buy the a 300 call option. This is the right to buy BTC for 300 dollars. Imagine at expiration, the delivery price is 400 dollar. Now this option will expire with a value of 100USD, which is 0.25BTC at the price of 400 dollar. So at expiration your account will be credited with 0.25BTC.
If you were the "seller" of the option, your account would be debited with 0.25BTC at expiration.
Any call options with an exercise price above 400 dollar would expire worthless.
You buy the 300 put option. This is the right to sell BTC for 300 dollar. Imagine at expiration the delivery price is 200 dollar. This option will expire with a value of 100USD, which is 0.5BTC with BTC priced at 200USD. So as owner of this option, your account will be credited with 0.5BTC at expiration.
If you were the seller of this option, your account would be debited with 0.5BTC.