Blockchain is a shared database. The data and information stored in it cannot be forged, leaves a full trace, can be traced back, is open and transparent, and is collectively maintained. You can think of blockchain as a shared, unchangeable electronic ledger that records transactions and tracks assets across a network. Those assets can be tangible (such as a house or a car) or intangible (such as intellectual property, patents and brands). Almost anything of value can be tracked and traded on a blockchain network, reducing risk and cost on every side. Today the largest application of blockchain technology is digital currency, because the essence of a payment is “moving an amount from account A to account B”. If people had a public ledger recording every transaction of every account up to now, then for any account anyone could calculate the amount it currently holds. Blockchain is exactly such a public ledger, keeping a complete record of all transactions. Blockchain originated with Bitcoin. On 1 November 2008, a person under the pseudonym Satoshi Nakamoto published “Bitcoin: A Peer-to-Peer Electronic Cash System”, setting out the architecture of an electronic cash system based on P2P networking, cryptography, timestamping and blockchain technology — the birth of Bitcoin. Two months later the theory became practice: on 3 January 2009 the first block, the genesis block with index 0, was created. A few days later, on 9 January 2009, block number 1 appeared and was linked to the genesis block, forming a chain — the birth of blockchain.

Unlike a centralized wallet (an exchange) where the private key is held by a third-party service provider, a decentralized wallet keeps the private key with the user. The assets are stored on the blockchain, and the user is the true holder of the digital currency. The wallet is only a tool that helps the user manage on-chain assets and read blockchain data, so it cannot control, steal or move your assets. For this reason a decentralized wallet is very hard to attack in a centralized way, and users do not need to worry about the wallet provider taking the assets or running away — as long as you keep your private key safe when you create the wallet, your assets remain on-chain and will still show up if you switch to another wallet. Note: once a decentralized wallet is lost or stolen, it cannot be recovered without a backup of the private key or mnemonic phrase, so always back up your private key safely and correctly.

The miner fee (gas fee), also called a network fee, is the fee paid to miners. When you transfer on a blockchain, the miners (or nodes) need to package your transaction and put it on the chain for the transaction to complete. This process consumes computing resources on the blockchain, which is why a miner fee is charged. On EVM-compatible chains the fee is determined by Gas Price (unit price) and the Gas Limit consumed (quantity), with the formula: Miner fee = Gas Limit × Gas Price. The Gas Limit mainly depends on how complex the operations in the smart contract are. The more operations, the higher the Gas Limit. Gas Price is set by the sender; the higher the Gas Price, the faster the transaction is packaged. Note: the network fee is ETH on Ethereum, BNB on BNB Chain, TRX on TRON, MATIC on Polygon, SOL on Solana and OKT on OKExChain; unused gas is refunded. The miner fee (network fee) charged by the transfer network varies with network conditions. Once a transaction is confirmed, the miner fee cannot be refunded whether or not the transaction succeeds. The miner fee is charged by the transfer network you choose — the imToken wallet does not charge any fee!

DeFi stands for Decentralized Finance. In contrast to traditional centralized finance, it refers to applications in every area of finance built on open, decentralized networks. Users no longer need a centralized institution to take part in financial markets; instead they can use open-source software on decentralized networks to acquire, trade and lend assets. In plain terms, it is a new financial system open to everyone, with no need for intermediaries such as banks. The goal of DeFi is to build a multi-layered financial system that recreates and improves on the existing financial system, based on blockchain technology and cryptocurrency. At present almost all DeFi projects run on the Ethereum blockchain, and smart contracts are the main building blocks of DeFi. The most common types of DeFi Dapps today include Compound, MakerDAO, Synthetix and decentralized exchanges such as Uniswap.