Learn Blockchain: Key Concepts Explained
Plain-English explainers of the concepts behind crypto – from consensus and finality to MEV, rollups and bridges. Start here to understand how things work under the hood.
Blockchain Consensus Mechanisms Compared Across Bitcoin, Ethereum, XRP Ledger and CometBFT
A comparative study of blockchain consensus mechanisms—including Bitcoin, Ethereum, Ripple, and Tendermint—evaluates peer-to-peer networks, native cryptocurrencies, transaction validation, block creation, consensus protocol design, and application development.…
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Where to start
Crypto has a reputation for jargon, but most concepts build on a few simple ideas. If you are new, read them roughly in this order:
- How a blockchain works – blocks, transactions, nodes and wallets.
- Consensus – how networks agree on one history (Proof of Work, Proof of Stake and others).
- Smart contracts and virtual machines – how code runs on-chain.
- Scaling – Layer 2 rollups, data availability and blobs.
- Market structure – transaction ordering, MEV, sequencers and intents.
Key terms in one place
| Term | Short definition |
|---|---|
| Block | A batch of transactions added to the chain at once |
| Consensus | The rules that let independent nodes agree on one history |
| Finality | The point after which a transaction cannot be reversed |
| Gas | The fee unit that pays for computation on a network |
| Mempool | Where pending transactions wait before inclusion in a block |
| MEV | Profit from including, excluding or reordering transactions |
| Rollup | A Layer 2 that executes transactions off-chain and posts data to a Layer 1 |
| Bridge | A system that moves assets or messages between chains |
| Oracle | A service that brings off-chain data, such as prices, on-chain |
Why concepts like MEV matter to users
Some topics sound academic but affect everyday users. MEV, for example, can make a trade execute at a worse price because a bot placed transactions around it. Understanding transaction ordering helps you choose settings, wallets and protocols that reduce this risk.
How we explain things
Each explainer starts with a short definition, then shows how the mechanism works with examples, and ends with trade-offs and open questions. We link to primary sources – protocol documentation, research papers and improvement proposals – wherever possible.
From concepts to practice
Each concept page links to deeper articles and real examples. After learning about consensus, read our blockchain reviews to see how different networks implement it. After learning about MEV and transaction ordering, our research shows how these mechanisms play out on Ethereum and rollups. This connection between theory and real data is the core of how we teach.
If a term is missing or an explanation is unclear, tell us through the contact page – reader questions often become new explainers.
Risks to keep in mind
Understanding a concept is not the same as being protected from its risks. Wallet security, phishing and smart-contract bugs cause most losses in crypto. Learn the basics of self-custody before moving real funds.
Frequently asked questions
What is the best way to learn blockchain?
Start with the fundamentals – transactions, blocks and consensus – then move to smart contracts and scaling. Reading a block explorer alongside explainers helps a lot.
What is MEV?
Maximal extractable value is the profit a block producer or searcher can capture by including, excluding or reordering transactions within a block.
What is finality in blockchain?
Finality is the point after which a confirmed transaction can no longer be reversed or reorganised out of the chain.
This page is for educational purposes only and is not financial, investment or tax advice. Crypto assets are volatile and you can lose all of the money you invest.
