Bitcoin is a digital asset and a payment system invented by Satoshi Nakamoto. Transactions are verified by network nodes through cryptography and recorded in a public dispersed ledger called a blockchain.
Bitcoin is unique in that there are a finite number of them: 21 million.
Bitcoins are created as a reward for a process known as mining. They can be exchanged for other currencies, products, and services.
As of February 2015, over 100,000 merchants and vendors accepted bitcoin as payment.
Bitcoin is halal if it is used to purchase goods or services that are halal. If bitcoin is used to purchase goods or services that are Haram, then it is not halal.
The majority of scholars seem to agree that bitcoin is halal if it is used for halal purposes. However, there is some disagreement on whether speculation with bitcoin is halal or Haram. Some scholars argue that speculation is Haram because it involves uncertainty and risk, which goes against the principles of Islam.
Other scholars argue that speculation is permissible because it can lead to positive outcomes, such as creating jobs and wealth. Ultimately, it is up to the individual Muslim to decide whether they want to speculate with bitcoin or not.