Free courseBeginner11 minCrypto Foundations
How Blockchain Works
A blockchain is the shared record that makes crypto possible. In this module you will see how blocks and hashes lock that record in place, how thousands of computers agree on it, and why your transaction needs fees and confirmations. You will also learn the limits of blockchains, so you are not fooled by big claims.
- 1Blocks and hashes: the building blocks of a blockchainWhat a block is, what a hash is, and how chaining blocks together with hashes makes past records very hard to change.2 min
- 2Distributed ledgers and consensus: proof of work vs. proof of stakeHow thousands of computers keep one shared ledger and agree on it, and the difference between proof of work and proof of stake.3 min
- 3Transactions, fees and confirmationsWhat happens after you press send: signing, waiting in line, paying network fees, and why confirmations and finality matter.3 min
- 4What blockchains cannot doBlockchains are powerful but limited: garbage in, garbage out, the oracle problem, scalability limits, and why on-chain does not mean trustworthy.3 min
Education, not investment advice. Crypto prices can fall sharply and most retail traders lose money. Practice in DUKOIN uses virtual USD with no real value.