In Bitcoin, rather than being managed or monitored by a central authority, a system has been created in which computers connected to the network collaborate on calculations and transaction validation to continuously maintain an accurate transaction ledger.
This mechanism is called P2P (peer-to-peer), but the question of what criteria to use to grant voting rights to the miners participating in this process became an issue. Bitcoin adopted Proof of Work (PoW) and decided to grant voting rights based on the amount of CPU computation performed.
The system works by requiring miners to perform massive computational work to verify that not only newly added transactions but also all previous transactions are correctly linked. The first miner to solve the given problem—finding a hash that meets specific conditions—is granted voting power (or a "block" in Bitcoin terms) and receives Bitcoin as a reward.
Concerns often arise regarding the possibility of a 51% attack, which refers to the act of gaining control of a majority of the network’s processing power to commit fraud.
However, this would require more than half of the network’s total CPU power, entailing significant costs such as procuring high-speed, high-performance computers and paying enormous electricity bills. Consequently, it is considered cost-inefficient and unlikely to occur.
