Bitcoin is a decentralized digital asset that is arguably the most popular, accounting for roughly half of all digital asset trading volume on most days. Bitcoin makes use of blockchain technology. Blockchain is not a monetary unit. It is the ledger that records all cryptocurrency transactions that are cryptographically verified and are open, secure, and accessible to all.
A transaction can be made by anyone and signed with a private key. It will be broadcasted to the unconfirmed transactions pool and verified by miners, who will be rewarded with the fee. A consensus mechanism approves each new block of transactions, which cannot be reversed after a certain amount of time (six blocks for Bitcoin). The main distinction is that Bitcoin employs proof of work (POW) consensus and a distinct transaction model. Blockchain technology does not impose any strict constraints on consensus, transaction models, or data transfer. Enterprise blockchain systems, for example, are used to build supply chains that do not contain any financial data.

Bitcoin and blockchain are often conflated but serve different purposes. Bitcoin is a cryptocurrency, a form of digital currency created in 2009 by an unknown person using the alias Satoshi Nakamoto. It enables peer-to-peer transactions without intermediaries, like banks, using a decentralized network.

Blockchain, on the other hand, is the underlying technology behind Bitcoin. It's a distributed ledger that records transactions across many computers to ensure security and transparency. While Bitcoin uses blockchain to operate, blockchain technology has broader applications beyond cryptocurrencies. It can be used in various fields such as supply chain management, healthcare, and finance for tasks like tracking assets, verifying identities, and automating contracts through smart contracts.