Beginner
5 min read

What Is a Blockchain?

A blockchain is a shared record of transactions maintained by many computers at once.

A shared ledger

A blockchain is a ledger — a list of transactions — copied across many independent computers. New transactions are grouped into blocks and appended in order, with each block cryptographically linked to the one before it.

Because thousands of participants hold copies and must agree on the next block, altering old history is extremely difficult.

What problem it solves

Normally a trusted institution keeps the record. A blockchain replaces that single record-keeper with rules and incentives, so participants who do not trust each other can still agree on who owns what.

What it does not solve

A blockchain guarantees the integrity of its record. It does not make a token valuable, does not make a project legitimate, and cannot reverse a transaction you were tricked into sending.

Why this matters

Nearly every crypto scam relies on the victim not understanding what the technology does and does not guarantee.

Terms used in this lesson

Blockchain
A shared transaction record maintained simultaneously by many independent computers.
See the full glossary
Written by
Suggested Investments Research Team
Content type
Educational article
Published
2026-09-13
Last reviewed
2026-09-13

Sources and methodology

What Is Bitcoin?

Educational content only. This lesson is not investment, tax or legal advice and does not recommend buying or selling any specific investment. All investing involves the risk of loss.