Bitcoin is an open protocol for transferring and independently verifying value. Its ledger is maintained by a distributed network, its history is ordered through proof of work, and its monetary rules are enforced by fully validating nodes.
Bitcoin separates verification from trust in an institution. Anyone may run the software, check the entire transaction history and reject blocks that violate the rules. Ownership is expressed through cryptographic keys rather than an account at a central operator.
The same word names both the network and its native unit. Capitalized “Bitcoin” usually refers to the system; lowercase “bitcoin” or BTC refers to the asset. One bitcoin is divisible into 100 million satoshis.
Bitcoin favors verifiability, predictable rules and resistance to unilateral control. This imposes costs: base-layer capacity is deliberately scarce, finality is probabilistic and users who hold their own keys carry operational responsibility.
No central issuer or operator
Rules independently checked by nodes
Fixed issuance schedule
Open-source and permissionless