Bitcoins are created by mining. Individuals or companies called miners process and complete ‘blocks’ of verified transactions using complex computer algorithms. The blocks are added to the blockchain and miners get new bitcoins as a reward. Mining involves solving complex computational puzzles, which require expensive equipment and a lot of electrical power. Under the bitcoin protocol, new bitcoins are produced at a predefined, gradually decreasing rate, which makes mining very competitive. The number of newly launched bitcoins is automatically halved every 210,000 blocks (approximately every four years) until all the 21 million bitcoinsare mined. It means the reward for mining new blocks is cut twice andminers get 50% less for verifying bitcoin transactions.