Being a decentralized system, Bitcoin relies on a mutually beneficial relationship with miners. Miners are individuals or organizations that use the processing power of various types of processing hardware, including ad hoc ones. Mining is the process of adding transaction data to the public ledger of past transactions with the purpose of providing a secure and tamper-resistant transaction. In return, the miners receive transactional fees and a subsidy of newly created coins. So, on the whole, it creates a vast and global network of miners ensuring that the system remains decentralized and motivating people to keep the system secure.
As the competition for earning bitcoins increases so does the rate at which bitcoins are generated. And as the rate of bitcoin generation increases so does the difficulty in finding new blocks in order to compensate and regulate the rate of block creation. That means it requires immense processing power to discover new blocks. As a consequence, Bitcoin farms have cropped up around the world employing huge arrays of circuits for the purpose of mining.
By November 2013, the total Bitcoin FLOPS was 64 exaFLOPS (that’s 64 x 1018 FLOPS or floating point operations per second, a measure of computing performance while calculating real numbers). To put that into perspective, the top 500 supercomputers combined have only 0.250 exaFLOPS (25 x 1015 FLOPS). That makes the entire network of Bitcoin 256 times faster than the top 500 supercomputers combined.