The Future of the Web: Web3 and Beyond

• A. All data is stored on a single central server owned by one company
• B. Control and data are distributed across many independent nodes instead of a single authority ✓
• C. Users are required to pay a monthly fee to a central provider
• D. Websites are hosted only on government-owned infrastructure

Why: Decentralization means no single entity controls the system; control and data are spread across many independent participants, which reduces single points of failure and reliance on a central authority.

• A. A type of programming language used to build websites
• B. A distributed ledger made of linked blocks of transactions, secured with cryptography ✓
• C. A search engine that indexes decentralized websites
• D. A browser extension that encrypts web traffic

Why: A blockchain is a distributed ledger in which transactions are grouped into blocks, each cryptographically linked to the previous one, and maintained by a network of participants rather than one central database.

• A. Its data is stored only on one encrypted hard drive
• B. Each block contains a hash of the previous block, so altering one block breaks the chain and is detected by other nodes ✓
• C. Administrators can delete records at any time to fix errors
• D. Transactions are kept secret from all network participants

Why: Because each block includes the cryptographic hash of the block before it, changing any historical record changes its hash and invalidates every subsequent block, which the honest majority of nodes would reject.

• A. A single transaction waiting to be confirmed
• B. A computer that participates in the network by storing and validating copies of the ledger ✓
• C. A smart contract that automatically pays out rewards
• D. A type of digital wallet used only for storing tokens

Why: A node is any computer running the blockchain software that keeps a copy of the ledger and independently verifies transactions and blocks, which is what makes the network decentralized.

• A. One company approves every transaction manually
• B. Network participants agree on the single valid version of the ledger using a defined set of rules ✓
• C. All users vote on the price of cryptocurrency each day
• D. The network shuts down until a majority of users log in

Why: Consensus is the process by which distributed participants agree on the state of the ledger without a central authority, using mechanisms such as proof of work or proof of stake to decide which transactions are valid.

• A. To prove ownership of an account without revealing any information
• B. To serve as an address that others can use to verify signatures and send assets to you
• C. To store your private data securely on a blockchain
• D. To encrypt all messages so that only you can read them

• A. A password that can be reset by a service provider if forgotten
• B. A secret value that proves ownership and is used to sign transactions
• C. A public string shared with others to receive payments
• D. A backup copy of your wallet's transaction history

• A. To encrypt transactions before they are broadcast to the network
• B. To generate and restore the private keys of a wallet
• C. To verify the identity of a website you are visiting
• D. To set a daily spending limit on your account

• A. Hot wallets cannot store cryptocurrency tokens of any kind
• B. Hot wallets are connected to the internet, increasing exposure to online attacks
• C. Hot wallets require manual approval for every transaction
• D. Hot wallets do not use cryptographic keys at all

• A. The blockchain network automatically transfers them to a recovery account
• B. A customer support team can restore access after verifying identity
• C. They can usually be recovered by contacting the bank that issued the wallet
• D. They generally become permanently inaccessible unless the key can be recovered

• A. A legally binding paper agreement signed by two parties
• B. A self-executing program stored on a blockchain that runs when predetermined conditions are met ✓
• C. A type of cryptocurrency wallet used for storing tokens
• D. A web page that automatically updates its content every hour

Why: A smart contract is code deployed on a blockchain that automatically executes its terms when specified conditions are satisfied, without needing a central intermediary.

• A. Bitcoin
• B. Ethereum ✓
• C. Litecoin
• D. Dogecoin

Why: Ethereum, launched in 2015, introduced a Turing-complete virtual machine that allowed developers to write and deploy general-purpose smart contracts, making it the leading smart contract platform.

• A. An application hosted on a single company's private servers
• B. An application whose backend runs on a peer-to-peer network, often using smart contracts ✓
• C. A mobile app that works only when offline
• D. A desktop program that cannot connect to the internet

Why: A dApp has its backend logic executed on a decentralized network, typically through smart contracts, rather than relying on a single centralized server controlled by one entity.

• A. They can be edited freely by any user at any time
• B. They are immutable, meaning their code generally cannot be changed ✓
• C. They automatically expire after one month
• D. They can only be executed by a bank

Why: Once deployed, smart contract code is generally immutable, which provides transparency and trust but also means bugs can be costly, so developers often use upgrade patterns or audits to mitigate risk.

• A. Electricity used to power the users' home computers
• B. Computational work needed to execute transactions and smart contract operations ✓
• C. A subscription to the Ethereum website
• D. Fees paid to the government for owning cryptocurrency

Why: Gas is the unit measuring computational effort on Ethereum. Users pay gas fees to compensate validators for processing transactions and running smart contract code.

• A. A physical card used to access websites
• B. A digital unit of value or ownership recorded on a blockchain ✓
• C. A password that encrypts personal data on the internet
• D. A type of web browser designed for decentralized apps

Why: A token is a digital unit that represents value, ownership, or access rights and is recorded on a blockchain ledger, which makes it verifiable and transferable without a central authority.

• A. New Financial Transaction
• B. Non-Fungible Token ✓
• C. Networked File Transfer
• D. Node Function Taxonomy

Why: NFT stands for Non-Fungible Token. 'Non-fungible' means each token is unique and cannot be exchanged one-for-one with another token, unlike currency where each unit is interchangeable.

• A. Impossible to copy or duplicate
• B. Interchangeable with other units of the same type ✓
• C. Stored only on a single server
• D. Free to download and use

Why: Fungible assets are interchangeable: one unit is equivalent to any other unit of the same kind. A dollar bill or one unit of a cryptocurrency like Bitcoin works this way, which is the opposite of an NFT.

• A. It guarantees the artwork can never be viewed by anyone else
• B. Its ownership record is stored on a blockchain that shows who holds it ✓
• C. It automatically gives the owner copyright over the underlying work
• D. It removes the file from the internet permanently

Why: An NFT's ownership history is recorded on a blockchain, creating a public, tamper-resistant record of who owns the token. However, owning the NFT does not automatically grant copyright or prevent others from viewing the image.

• A. Owning an NFT always gives you the legal copyright to the associated file
• B. An NFT is a record of ownership that may not include rights to the underlying content ✓
• C. NFTs can only be created by large corporations
• D. Once minted, an NFT cannot be bought or sold

Why: An NFT typically points to content and records ownership of the token itself, but the buyer may not gain copyright or usage rights to the underlying file. The terms attached to each NFT determine what rights, if any, the owner receives.

• A. Distributed Application Operation
• B. Decentralized Autonomous Organization ✓
• C. Digital Asset Ownership
• D. Distributed Access Oversight

Why: DAO stands for Decentralized Autonomous Organization, a group whose rules are encoded in smart contracts and whose decisions are made collectively by token holders rather than a central management hierarchy.

• A. By submitting paper ballots to a central office
• B. By voting on proposals using governance tokens ✓
• C. By being appointed by a company CEO
• D. By purchasing shares from a stock exchange

Why: Most DAOs use governance tokens to give members voting power on proposals, with the weight of a vote often tied to the number of tokens held.

• A. They replace all human participation entirely
• B. They automatically execute rules and transactions once conditions are met ✓
• C. They serve only as marketing tools for the organization
• D. They store the organization's physical assets

Why: Smart contracts are self-executing code on a blockchain that enforce the DAO's rules and carry out approved actions, such as transferring funds, without needing a central intermediary.

• A. Lack of any digital record of decisions
• B. Low voter turnout and concentration of voting power among large token holders ✓
• C. Inability to hold any form of online discussion
• D. Requirement to register with a central government

Why: Many DAOs struggle with low participation from members and with voting power concentrating among a few large token holders, which can undermine the goal of broad, decentralized decision-making.

• A. A rulebook that governs member behavior
• B. A shared pool of funds controlled collectively by the DAO ✓
• C. A list of members who have been banned
• D. The software developers who maintain the code

Why: A DAO treasury is a pool of cryptocurrency or other assets held collectively, which the community typically votes on how to spend to fund projects, grants, or operations.

• A. To replace the underlying Layer 1 blockchain entirely
• B. To process transactions off the main chain in order to increase throughput and reduce fees ✓
• C. To store all historical blockchain data permanently
• D. To create new cryptocurrencies independent of the base network

Why: Layer 2 solutions handle transactions off the main (Layer 1) chain and then settle or anchor results back to it. This increases transaction throughput and lowers costs while still inheriting the security of the underlying blockchain.

• A. The difficulty of choosing between three different consensus algorithms
• B. The tradeoff among decentralization, security, and scalability, where improving one often compromises the others ✓
• C. The three stages of a blockchain upgrade process
• D. The challenge of supporting three different programming languages

Why: The scalability trilemma, popularized by Ethereum's Vitalik Buterin, states that blockchains struggle to simultaneously maximize decentralization, security, and scalability. Many design choices sacrifice one property to strengthen the other two.

• A. A method of permanently deleting old blocks from the chain
• B. A Layer 2 system that executes transactions off-chain and posts compressed transaction data or proofs to Ethereum ✓
• C. A type of wallet that automatically stakes tokens
• D. A governance proposal for changing block size

Why: Rollups bundle many transactions together, execute them off-chain, and submit compressed data or validity proofs back to Ethereum's Layer 1. This keeps security tied to the main chain while greatly reducing the cost per transaction.

• A. The ability of different blockchains and applications to communicate and exchange data or value with each other ✓
• B. The process of mining multiple cryptocurrencies at the same time
• C. A requirement that all nodes run identical hardware
• D. The practice of encrypting data before storing it on a server

Why: Interoperability refers to the ability of separate blockchain networks and applications to share information and assets. Cross-chain bridges and messaging protocols are common tools that enable it.

• A. A blockchain that runs parallel to a main chain with its own consensus mechanism, connected to it through a two-way bridge ✓
• B. A temporary test network that is never connected to a mainnet
• C. A rollup that only supports a single smart contract
• D. A private database owned by one company

Why: A sidechain is an independent blockchain with its own consensus rules, linked to a main chain through a bridge that allows assets to move between them. Unlike rollups, sidechains typically do not inherit the main chain's security directly.

• A. Making web pages load faster through better caching
• B. Adding machine-readable meaning to web data so computers can interpret relationships between information
• C. Replacing HTML with a binary format for mobile devices
• D. Encrypting all web traffic by default

• A. CSS
• B. JavaScript
• C. RDF
• D. FTP

• A. Web3 removes all user interaction from websites
• B. Web3 emphasizes decentralization, blockchain-based ownership, and user control over data rather than centralized platforms
• C. Web3 requires users to download a desktop application for every site
• D. Web3 is simply an older version of the web that predates HTML

• A. AI replaces all web browsers entirely
• B. AI can help interpret, organize, and personalize information, and can work alongside semantic data to make the web more understandable to machines
• C. AI makes hyperlinks obsolete by eliminating the need for any navigation
• D. AI prevents any data from being shared between websites

• A. Linked data is a competitor to the Semantic Web with no shared principles
• B. Linked data applies Semantic Web principles by publishing and connecting structured data using URIs so that datasets can reference one another
• C. Linked data means storing all files on a single central server
• D. Linked data refers only to social media follower networks