As specified by the Bitcoin protocol, each miner is rewarded by each block mined.  Currently, that reward is 12.5 new Bitcoins for each block mined. The Bitcoin block mining reward halves every 210,000 blocks, when the coin reward will decrease from 12.5 to 6.25 coins.  Currently, the total number of Bitcoins left to be mined amounts to 4,293,388. This means that 16,706,613 Bitcoins are in circulation, and that the total number of blocks available until mining reward is halved is 133,471 blocks till 11:58:04 12th Jun, 2020 When the mining reward will be halved.

Because it's similar to gold mining in that the bitcoins exist in the protocol's design (just as the gold exists underground), but they haven't been brought out into the light yet (just as the gold hasn't yet been dug up). The bitcoin protocol stipulates that 21 million bitcoins will exist at some point. What "miners" do is bring them out into the light, a few at a time.
If Eve offers to pay Alice a bitcoin in exchange for goods and signs a corresponding transaction, it is still possible that she also creates a different transaction at the same time sending the same bitcoin to Bob. By the rules, the network accepts only one of the transactions. This is called a race attack, since there is a race which transaction will be accepted first. Alice can reduce the risk of race attack stipulating that she will not deliver the goods until Eve's payment to Alice appears in the blockchain.[15]
Although BitFury claims to be producing chips whose performance is nearly identical to those used in the S9, the company has packaged them into a very different product. Called the BlockBox, it’s a complete bitcoin-mining data center that BitFury ships to customers in a storage container. Beijing’s Canaan Creative is still selling mining rigs to the public, but it offers only one product, the AvalonMiner 741, and it’s only half as powerful and slightly less efficient than the S9.
In Charles Stross' 2013 science fiction novel, Neptune's Brood, the universal interstellar payment system is known as "bitcoin" and operates using cryptography.[235] Stross later blogged that the reference was intentional, saying "I wrote Neptune's Brood in 2011. Bitcoin was obscure back then, and I figured had just enough name recognition to be a useful term for an interstellar currency: it'd clue people in that it was a networked digital currency."[236]
The rise in the value of bitcoin and other cryptocurrencies in recent years has made cryptocurrency mining a lucrative activity. Cryptocurrency mining uses computing power to compete against other computers to solve complex math problems, with that effort rewarded with bits of cryptocurrencies. That computing power helps create a distributed, secure and transparent network ledger — commonly known as a blockchain — on which applications such as bitcoin can be built.

These dynamics have resulted in a race among miners to amass the fastest, most energy-efficient chips. And the demand for faster equipment has spawned a new industry devoted entirely to the computational needs of Bitcoin miners. Until late 2013, generic graphics cards and field-programmable gate arrays (FPGAs) were powerful enough to put you in the race. But that same year companies began to sell computer chips, called application-specific integrated circuits (ASICs), which are specifically designed for the task of computing the Bitcoin hashing algorithm. Today, ASICs are the standard technology found in every large-scale facility, including the mining farm in Ordos. When Bitmain first started making ASICs in 2013, the field was thick with competitors—BitFury, a multinational ASIC maker; KnCMiner in Stockholm; Butterfly Labs in the United States; Canaan Creative in Beijing; and about 20 other companies spread around China.
Client-side encryption means all of your data is encrypted on your device before any of your information touches the servers. Once your account and everything in it has been encrypted, we automatically back it up. We can’t access your assets or any other information in any usable form but if anything happens to your device, you can just download the Edge app on a new device, enter your username and password and your assets are right where you left them.
Bitcoin mining is the process of updating the ledger of Bitcoin transactions known as the blockchain. Mining is done by running extremely powerful computers (known as ASICs) that race against other miners in an attempt to guess a specific number. The first miner to guess the number gets to update the ledger of transactions and also receives a reward of newly minted Bitcoins (currently the reward is 12.5 Bitcoins).
Numerous people have been suggested as possible Satoshi Nakamotos by major media outlets. On Oct. 10, 2011, The New Yorker published an article speculating that Nakamoto might be Irish cryptography student Michael Clear, or economic sociologist Vili Lehdonvirta. A day later, Fast Company suggested that Nakamoto could be a group of three people – Neal King, Vladimir Oksman and Charles Bry – who together appear on a patent related to secure communications that was filed two months before was registered. A Vice article published in May 2013 added more suspects to the list, including Gavin Andresen, the Bitcoin project’s lead developer; Jed McCaleb, co-founder of now-defunct Bitcoin exchange Mt. Gox; and famed Japanese mathematician Shinichi Mochizuki. 

What bitcoin miners actually do could be better described as competitive bookkeeping. Miners build and maintain a gigantic public ledger containing a record of every bitcoin transaction in history. Every time somebody wants to send bitcoins to somebody else, the transfer has to be validated by miners: They check the ledger to make sure the sender isn’t transferring money she doesn’t have. If the transfer checks out, miners add it to the ledger. Finally, to protect that ledger from getting hacked, miners seal it behind layers and layers of computational work—too much for a would-be fraudster to possibly complete.
Every 2,016 blocks (approximately 14 days at roughly 10 min per block), the difficulty target is adjusted based on the network's recent performance, with the aim of keeping the average time between new blocks at ten minutes. In this way the system automatically adapts to the total amount of mining power on the network.[3]:ch. 8 Between 1 March 2014 and 1 March 2015, the average number of nonces miners had to try before creating a new block increased from 16.4 quintillion to 200.5 quintillion.[80]
Bitcoin's origin story sounds like something out of science fiction: It was launched in 2008 on the heels of a white paper published by the mysterious Satoshi Nakamoto, whose real identity – and country of origin – are unknown. Nakamoto conceived of Bitcoin as a currency that was 1) encrypted; 2) decentralized, i.e. it was ungoverned and did not belong to any nation; and 3) a digital "distributed ledger," such that everyone can verify online the legitimacy of transactions.
Satoshi's anonymity often raises unjustified concerns because of a misunderstanding of Bitcoin's open-source nature. Everyone has access to all of the source code all of the time and any developer can review or modify the software code. As such, the identity of Bitcoin's inventor is probably as relevant today as the identity of the person who invented paper.

This spring, Bitmain caused a minor uproar when a developer found a “backdoor,” called Antbleed, in the firmware of Bitmain’s S9 Antminers. The backdoor could have been used by the company to track the location of its machines and shut them down remotely. While no computer purchaser would find such a vulnerability acceptable, it’s particularly troubling for Bitcoin.

Carlson has become the face of the Mid-Columbia Basin crypto boom. Articulate, infectiously optimistic, with graying hair and a trim beard, the Microsoft software developer-turned-serial entrepreneur has built a series of mines, made (and lost) several bitcoin fortunes and endured countless setbacks to become one of the region’s largest players. Other local miners credit Carlson for launching the basin’s boom, back in 2012, when he showed up in a battered Honda in the middle of a snowstorm and set up his servers in an old furniture store. Carlson wouldn’t go that far, but the 47-year-old was one of the first people to understand, back when bitcoin was still mainly something video gamers mined in their basements, that you might make serious money mining bitcoin at scale—but only if you could find a place with cheap electricity.
Although it is possible to handle bitcoins individually, it would be unwieldy to require a separate transaction for every bitcoin in a transaction. Transactions are therefore allowed to contain multiple inputs and outputs, allowing bitcoins to be split and combined. Common transactions will have either a single input from a larger previous transaction or multiple inputs combining smaller amounts, and one or two outputs: one for the payment, and one returning the change, if any, to the sender. Any difference between the total input and output amounts of a transaction goes to miners as a transaction fee.[2]
In parts of the basin, utility crews now actively hunt unpermitted miners, in a manner not unlike the way police look for indoor cannabis farms. The biggest giveaway, Stoll says, is a sustained jump in power use. But crews have learned to look, and listen, for other telltales, such as “fans that are exhausting out of the garage or a bedroom.” In any given week, the utility flushes out two to five suspected miners, Stoll says. Some come clean. They pay for permits and the often-substantial wiring upgrades, or they quit. But others quietly move their servers to another residential location and plug back in. “It’s a bit of a cat-and-mouse game,” Stoll admits.

Jump up ^ Christin, Nicolas (2013). Traveling the Silk Road: A Measurement Analysis of a Large Anonymous Online Marketplace (PDF). Carnegie Mellon INI/CyLab. p. 8. Retrieved 22 October 2013. we suggest to compare the estimated total volume of Silk Road transactions with the estimated total volume of transactions at all Bitcoin exchanges (including Mt.Gox, but not limited to it). The latter corresponds to the amount of money entering and leaving the Bitcoin network, and statistics for it are readily available... approximately 1,335,580 BTC were exchanged on Silk Road... approximately 29,553,384 BTC were traded in Bitcoin exchanges over the same period... The only conclusion we can draw from this comparison is that Silk Road-related trades could plausibly correspond to 4.5% to 9% of all exchange trades

The proof-of-work system, alongside the chaining of blocks, makes modifications of the blockchain extremely hard, as an attacker must modify all subsequent blocks in order for the modifications of one block to be accepted.[81] As new blocks are mined all the time, the difficulty of modifying a block increases as time passes and the number of subsequent blocks (also called confirmations of the given block) increases.[64]