What You Need to Mine Bitcoins ?

 What You Need to Mine Bitcoins

Although individuals were able to compete for blocks with a regular at-home personal computer early on in Bitcoin's history, this is no longer the case. The reason for this is that the difficulty of mining Bitcoin changes over time.

In order to ensure the blockchain functions smoothly and can process and verify transactions, the Bitcoin network aims to have one block produced every 10 minutes or so. However, if there are 1 million mining rigs competing to solve the hash problem, they'll likely reach a solution faster than a scenario in which 10 mining rigs are working on the same problem. For that reason, Bitcoin is designed to evaluate and adjust the difficulty of mining every 2,016 blocks, or roughly every two weeks.1

When there is more computing power collectively working to mine for bitcoins, the difficulty level of mining increases in order to keep block production at a stable rate. Less computing power means the difficulty level decreases. At today's network size, a personal computer mining for bitcoin will almost certainly find nothing. 

Why Bitcoin Needs Miners?

 Why Bitcoin Needs Miners?

Blockchain "mining" is a metaphor for the computational work that nodes in the network undertake in hopes of earning new tokens. In reality, miners are essentially getting paid for their work as auditors. They are doing the work of verifying the legitimacy of Bitcoin transactions. This convention is meant to keep Bitcoin users honest and was conceived by Bitcoin's founder, Satoshi Nakamoto.1 By verifying transactions, miners are helping to prevent the "double-spending problem." 

Double spending is a scenario in which a Bitcoin owner illicitly spends the same bitcoin twice. With physical currency, this isn't an issue: When you hand someone a $20 bill to buy a bottle of vodka, you no longer have it, so there's no danger you could use that same $20 bill to buy lotto tickets next door. Though counterfeit cash is possible, it is not exactly the same as literally spending the same dollar twice. With digital currency, however, as the Investopedia dictionary explains, "there is a risk that the holder could make a copy of the digital token and send it to a merchant or another party while retaining the original."

Let's say you had one legitimate $20 bill and one counterfeit of that same $20. If you were to try to spend both the real bill and the fake one, someone who took the trouble of looking at both of the bills' serial numbers would see that they were the same number, and thus one of them had to be false. What a blockchain miner does is analogous to that—they check transactions to make sure that users have not illegitimately tried to spend the same bitcoin twice. This isn't a perfect analogy—we'll explain in more detail below.

•Only 1 megabyte of transaction data can fit into a single bitcoin block. The 1MB limit was set by Satoshi Nakamoto, and this has become a matter of controversy because some miners believe the block size should increase to accommodate more data, which would effectively mean that the Bitcoin network could process and verify transactions more quickly.