Proof of work (PoW) is a form of cryptographic proof in which one party proves to others that a certain amount of a specific computational effort has been expended. Verifiers can subsequently confirm this expenditure with minimal effort on their part. The concept was invented by Moni Naor and Cynthia Dwork in 1993 as a way to deter denial-of-service attacks and other service abuses such as spam on a network by requiring some work from a service requester, usually meaning processing time by a computer. The term "proof of work" was first coined and formalized in a 1999 paper by Markus Jakobsson and Ari Juels. The concept was adapted to digital tokens by Hal Finney in 2004 through the idea of "reusable proof of work" using the 160-bit secure hash algorithm 1 (SHA-1).
A smart contract is a computer program or a transaction protocol that is intended to automatically execute, control or document events and actions according to the terms of a contract or an agreement. The objectives of smart contracts are the reduction of need for trusted intermediators, arbitration costs, and fraud losses, as well as the reduction of malicious and accidental exceptions. Smart contracts are commonly associated with cryptocurrencies, and the smart contracts introduced by Ethereum are generally considered a fundamental building block for decentralized finance (DeFi) and NFT applications.
Litecoin is a decentralized peer-to-peer cryptocurrency and open-source software project released under the MIT/X11 license. Inspired by Bitcoin, Litecoin was among the earliest altcoins, starting in October 2011. In technical details, the Litecoin main chain shares a slightly modified Bitcoin codebase. The practical effects of those codebase differences are lower transaction fees, faster transaction confirmations, and faster mining difficulty retargeting. Due to its underlying similarities to Bitcoin, Litecoin has historically been referred to as the "silver to Bitcoin's gold." In 2022, Litecoin added optional privacy features via soft fork through the MWEB upgrade.
Ethereum is a decentralized blockchain with smart contract functionality. Ether is the native cryptocurrency of the platform. Among cryptocurrencies, ether is second only to bitcoin in market capitalization. It is open-source software.
A decentralized autonomous organization (DAO), sometimes called a decentralized autonomous corporation (DAC), is an organization managed in whole or in part by decentralized computer program, with voting and finances handled through a blockchain. In general terms, DAOs are member-owned communities without centralized leadership. The precise legal status of this type of business organization is unclear.
Circle is a peer-to-peer payments technology company that now manages stablecoin USDC, a cryptocurrency the value of which is pegged to the U.S. dollar. It was founded by Jeremy Allaire and Sean Neville in October 2013. Circle is headquartered in Boston, Massachusetts. USDC, the second largest stablecoin worldwide, is designed to hold at or near a stable price of $1. The majority of its stablecoin collateral is held in short-term U.S. government securities.
The DAO was a digital decentralized autonomous organization and a form of investor-directed venture capital fund. After launching in April 2016 via a token sale, it became one of the largest crowdfunding campaigns in history, but it ceased activity after much of its funds were taken in a hack in June 2016.
A decentralised application is an application that can operate autonomously, typically through the use of smart contracts, that run on a decentralized computing, blockchain or other distributed ledger system. Like traditional applications, DApps provide some function or utility to its users. However, unlike traditional applications, DApps operate without human intervention and are not owned by any one entity, rather DApps distribute tokens that represent ownership. These tokens are distributed according to a programmed algorithm to the users of the system, diluting ownership and control of the DApp. Without any one entity controlling the system, the application is therefore decentralised.
Ethereum Classic is a blockchain-based distributed computing platform that offers smart contract (scripting) functionality. It is open source and supports a modified version of Nakamoto consensus via transaction-based state transitions executed on a public Ethereum Virtual Machine (EVM).
Cardano is a public blockchain platform. It is open-source and decentralized, with consensus achieved using proof of stake. It can facilitate peer-to-peer transactions with its internal cryptocurrency, ADA.
The Bitcoin scalability problem refers to the limited capability of the Bitcoin network to handle large amounts of transaction data on its platform in a short span of time. It is related to the fact that records in the Bitcoin blockchain are limited in size and frequency.
A cryptocurrency wallet is a device, physical medium, program or an online service which stores the public and/or private keys for cryptocurrency transactions. In addition to this basic function of storing the keys, a cryptocurrency wallet more often offers the functionality of encrypting and/or signing information. Signing can for example result in executing a smart contract, a cryptocurrency transaction, identification, or legally signing a 'document'.
Polkadot is a blockchain platform and cryptocurrency. The native cryptocurrency for the Polkadot blockchain is the DOT. It is designed to allow blockchains to exchange messages and perform transactions with each other without a trusted third-party. This allows for cross-chain transfers of data or assets, between different blockchains, and for decentralized applications (DApps) to be built using the Polkadot Network.
An airdrop is an unsolicited distribution of a cryptocurrency token or coin, usually for free, to numerous wallet addresses. Airdrops are often associated with the launch of a new cryptocurrency or a DeFi protocol, primarily as a way of gaining attention and new followers, resulting in a larger user base and a wider disbursement of coins. Airdrops have been a more important part of ICOs since crypto entrepreneurs have started doing private sales instead of public offerings to raise initial capital. One example of this is by the company Omise, which gave away five percent of its OmiseGO cryptocurrency to Ethereum holders in September 2017.
MetaMask is a software cryptocurrency wallet used to interact with the Ethereum blockchain. It allows users to access their Ethereum wallet through a browser extension or mobile app, which can then be used to interact with decentralized applications. MetaMask is developed by ConsenSys Software Inc., a blockchain software company focusing on Ethereum-based tools and infrastructure.
CryptoPunks is a non-fungible token (NFT) collection on the Ethereum blockchain. The project was launched in June 2017 by the Larva Labs studio, a two-person team consisting of Canadian software developers Matt Hall and John Watkinson. The experimental project was inspired by the London punk scenes, the cyberpunk movement, and electronic music artists Daft Punk. The crypto art blockchain project was an inspiration for the ERC-721 standard for NFTs and the modern crypto art movement, which has since become a part of the cryptocurrency and decentralized finance ecosystems on multiple blockchains.
Stacks, formerly Blockstack, is a blockchain platform for smart contracts, decentralized finance ("DeFi"), non-fungible tokens (NFTs), and decentralized apps ("DApps"). Stacks blockchain is a layer for bitcoin similar to the Lightning Network.
A rare Pepe or RarePepe is a variation on the "Pepe the Frog" internet meme, itself based on a character created by Matt Furie. The related Rare Pepe crypto project, created by various artists worldwide between 2016 and 2018, was based on the aforementioned meme and traded as non-fungible tokens (NFTs) recorded on the CounterParty platform. A total of 1,774 official cards were released for the project across 36 series.
Solana is a blockchain platform which uses a proof-of-stake mechanism to provide smart contract functionality. Its native cryptocurrency is SOL.
Colored Coins is an open-source protocol that allows users to represent and manipulate immutable digital resources on top of Bitcoin transactions. They are a class of methods for representing and maintaining real-world assets on the Bitcoin blockchain, which may be used to establish asset ownership. Colored coins are bitcoins with a mark on them that specifies what they may be used for. Colored coins are also considered the initial step toward NFTs built on top of the Bitcoin network.
