<\/span><\/h3>\n\n\n\nThere are two types of accounts on Ethereum: user accounts and contracts. Both types have an ETH balance, may send ETH to any account, may call any public function of a contract or create a new contract, and are identified on the blockchain and in the state by their address.<\/p>\n\n\n\n
User accounts are the only type that may create transactions. For a transaction to be valid, it must be signed using the sending account’s private key, the 64-character hexadecimal string from which the account’s address is derived. The algorithm used to produce the signature allows one to derive the signer’s address from the signature without knowing the private key.<\/p>\n\n\n\n
Contracts are the only type of account that has associated code and contract storage. A contract function may take arguments and may have return values. Within the body of a function, in addition, to control flow, statements, a contract’s code may include instructions to send ETH, read from and write to its storage, create temporary storage (memory) that dies at the end of the function, perform arithmetic and hashing operations, call its own functions, call public functions of other contracts, create new contracts, and query information about the current transaction or the blockchain.<\/p>\n\n\n\n
<\/span>Gas<\/span><\/h3>\n\n\n\nGas refers to the transaction fees, or pricing value, required to successfully conduct a transaction or execute a contract on the Ethereum blockchain platform. The Ethereum blockchain requires “gas” to keep itself running in the same way that a car needs gasoline to move. All transactions on the Ethereum network cost a certain amount of gas, depending on the current demand and the size and speed of the contract one is trying to execute.<\/p>\n\n\n\n
<\/span>Applications<\/span><\/h3>\n\n\n\n<\/span>Contract source code<\/span><\/h4>\n\n\n\nEthereum’s smart contracts are comparable to legal contracts outside of blockchain technology. One issue related to using smart contracts on a public blockchain network is that bugs are visible to all but cannot be fixed quickly. A centralized system such as your computer can provide certain guarantees that a public blockchain cannot. For example, there could be an assumption that the state of the contract does not change after a withdrawal however, If the owner wanted to, he could monitor the network for submissions. When he detects an unprocessed transaction containing a valid submission, he could then submit one himself that lowers the bounty. There are solutions currently being worked out; a soon-to-be-released tool for automated detection of these exploits.<\/p>\n\n\n\n
<\/span>ERC-20 Tokens<\/span><\/h4>\n\n\n\nThe ERC-20 (Ethereum Request for Comments 20) Token Standard allows for fungible tokens on the Ethereum blockchain. The standard provides functions including the transfer of tokens from one account to another, getting the current token balance of an account, and getting the total supply of the token available on the network. Smart contracts that correctly implement ERC-20 processes are called ERC-20 Token Contracts and help keep track of the created tokens on Ethereum.<\/p>\n\n\n\n
<\/span>Non-fungible Tokens (NFTs)<\/span><\/h4>\n\n\n\nEthereum also allows for the creation of unique and indivisible tokens, NFTs. NFTs have been used to represent such things as collectibles, digital art, sports memorabilia, virtual real estate, gaming items. The first NFT project, Etheria, a 3D map of tradable and customizable hexagonal tiles, was deployed to<\/p>\n\n\n\n
<\/span>Decentralized Finance (DeFi)<\/span><\/h4>\n\n\n\nDecentralized Finance offers traditional financial instruments in a decentralized framework outside of companies’ and governments’ control, such as money market funds which let users earn interest. Decentralized finance applications are typically accessed through a Web3-enabled browser extension or application which allows users to directly interact with the Ethereum blockchain through a website.<\/p>\n\n\n\n
<\/span>Ethereum 2.0