Introduction
This glossary demystifies essential Ethereum and blockchain terminology, providing clear definitions for developers and enthusiasts. The terms are organized thematically for easy navigation.
Core Concepts
Blockchain Fundamentals
- Blockchain: A continuously growing sequence of data blocks containing transaction histories, secured through cryptographic proof-of-work.
- Block: A data package containing transactions (0 or more), parent block hash, and additional metadata. Each block links cryptographically to its predecessor.
- Genesis Block: The first block in any blockchain.
- Mining: The process of validating transactions and creating new blocks in exchange for Ether rewards.
Ethereum-Specific Terms
- Ether (ETH): Ethereum's native cryptocurrency used to pay for transaction fees and computational services.
- Gas: The unit measuring computational effort required for operations on the Ethereum Virtual Machine (EVM).
- EVM: Ethereum's runtime environment for executing smart contract bytecode across its decentralized network.
- Address: A 20-byte identifier representing an Ethereum account (e.g.,
0xcd2a3d9f...).
Account Types
- EOA (Externally Owned Account): Controlled by private keys, used for sending ETH and messages.
- Contract Account: Contains executable code triggered by transactions or other contracts.
Transaction Mechanics
- Transaction Fee: Calculated as
gas used * gas price, paid to miners for processing. - Nonce: A unique number per transaction preventing replay attacks.
- Uncle Block: A valid but stale block that receives partial rewards to improve network security.
Smart Contracts & DApps
- Smart Contract: Self-executing code stored on-chain with predefined rules.
- DApp (Decentralized Application): Applications operating without centralized control, enabling peer-to-peer interactions.
- Solidity: Ethereum's primary programming language for writing smart contracts.
Consensus Mechanisms
- PoW (Proof-of-Work): Mining-based validation requiring computational effort.
- PoS (Proof-of-Stake): Upcoming validation method where validators stake ETH to participate.
- Casper: Ethereum's PoS implementation enforcing validator deposits for security.
Networks & Clients
- Testnet: Ethereum's practice network (e.g., Morden) for development testing.
- Geth: Go-language Ethereum client implementation.
- Parity: Rust-language alternative Ethereum client.
Advanced Topics
- Sharding: Partitioning the blockchain to improve scalability.
- Merkle Patricia Tree: A cryptographic data structure for efficient (key,value) storage.
- GHOST Protocol: Chain selection algorithm that rewards uncle blocks to enhance decentralization.
FAQs
Q: What’s the difference between Ether and Gas?
A: Ether is Ethereum’s currency, while Gas measures computational work priced in ETH.
Q: How do smart contracts communicate?
A: Via messages—virtual objects containing data between contracts.
Q: Why do uncle blocks receive rewards?
A: To incentivize miners with slower connections and reduce centralization risks.