Blockchain
A shared, append-only digital ledger that records transactions across many computers so entries are very hard to alter retroactively.
Definition
A blockchain is a database structured as a chain of cryptographically linked blocks, each containing a batch of transactions and a hash of the previous block. Copies are maintained by a distributed network that agrees on the ledger's state through a consensus mechanism such as proof-of-work or proof-of-stake, making recorded history extremely difficult to rewrite. In gambling, blockchains underpin cryptocurrency payments, on-chain betting contracts and the public verification of some fairness schemes. Being on a blockchain makes transactions transparent and tamper-resistant, but it does not make a casino trustworthy, licensed or fair on its own.
Worked example
When you withdraw Bitcoin from a crypto casino, the payment is recorded as a transaction in a block that anyone can inspect on a public blockchain explorer.
Why it matters
It is the foundational concept behind everything in crypto gambling; learners need it to reason about transparency and its limits, and professionals to assess auditability and traceability.