Layer 2 (L2) is a collective term for off-chain scaling solutions that inherit the security of a Layer 1 blockchain while processing transactions faster and cheaper. Major categories include Optimistic Rollups (Arbitrum, Optimism) and ZK Rollups (StarkNet, zkSync).
Proof of Work (PoW) is the original blockchain consensus mechanism, made famous by Bitcoin. Miners compete to solve computationally expensive puzzles to validate transactions and add blocks to the chain. The difficulty automatically adjusts to maintain consistent block times.
Proof of Stake (PoS) is a blockchain consensus mechanism where validators are selected to create new blocks based on the amount of cryptocurrency they stake as collateral, rather than through energy-intensive computation. It is significantly more energy-efficient than Proof of Work.
Cryptocurrency mining is the process of validating blockchain transactions and adding new blocks by solving computationally intensive mathematical puzzles. Miners are rewarded with newly created cryptocurrency. Bitcoin mining has evolved from home CPUs to industrial ASIC farms consuming gigawatts of power.
Smart contracts are self-executing programs stored on a blockchain that automatically enforce the terms of an agreement when predefined conditions are met. They are the foundation of DeFi, NFTs, and decentralised autonomous organisations.
Chainlink is the leading decentralised oracle network, providing smart contracts with secure access to real-world data, APIs, and external computation. It is the essential infrastructure layer connecting blockchains to off-chain information such as stock prices, weather data, and sports results.
A blockchain is a distributed, append-only ledger of records (blocks) chained together cryptographically. Each block contains a cryptographic hash of the previous block, ensuring immutability. Bitcoin introduced the first practical implementation in 2008, solving the double-spend problem without a central authority.
The Lightning Network is a Layer 2 payment protocol built on top of Bitcoin. It enables near-instant, near-free Bitcoin transactions by creating off-chain payment channels between parties. Only the opening and closing of channels are recorded on the Bitcoin blockchain.
Zero-knowledge proofs (ZKPs) are cryptographic methods that allow one party to prove they know something without revealing what that thing is. In blockchain, they enable both privacy and scaling — proving off-chain computation is correct without re-executing it on-chain.
MetaMask is the world's most popular Ethereum wallet, available as a browser extension and mobile app. It allows users to interact with decentralised applications directly from their browser, store Ethereum and ERC-20 tokens, and sign transactions. With over 30 million monthly active users, it is the primary gateway to Web3.
Solidity is the primary programming language for writing Ethereum smart contracts. It is a statically-typed, contract-oriented language with syntax influenced by JavaScript and C++. It powers virtually all DeFi protocols, NFT contracts, and DAOs on Ethereum and EVM-compatible chains.