Ethereum is a smart contract platform that enables developers to build tokens and decentralized applications (dapps). ETH is the native currency for the Ethereum platform and also works as the transaction fees to miners on the Ethereum network. Ethereum is the pioneer for blockchain based smart contracts. Smart contract is essentially a computer code that runs exactly as programmed without any possibility of downtime, censorship, fraud or third-party interference. It can facilitate the exchange of money, content, property, shares, or anything of value. When running on the blockchain a smart contract becomes like a self-operating computer program that automatically executes when specific conditions are met. Ethereum allows programmers to run complete-turing smart contracts that is capable of any customizations. Rather than giving a set of limited operations, Ethereum allows developers to have complete control over customization of their smart contract, giving developers the power to build unique and innovative applications. Ethereum being the first blockchain based smart contract platform, they have gained much popularity, resulting in new competitors fighting for market share. The competitors includes: Ethereum Classic which is the oldchain of Ethereum, Qtum, EOS, Neo, Icon, Tron and Cardano. Ethereum wallets are fairly simple to set up with multiple popular choices such as myetherwallet, metamask, and Trezor. Read here for more guide on using ethereum wallet: How to Use an Ethereum Wallet
Dai is a stablecoin. It is an Ethereum ERC20 token that is pegged to $1 USD — every Dai is worth $1, and will always be worth $1, regardless of how much Dai is in existence. There is no centralized authority like Tether that backs its value, and no traditional bank that backs each Dai with a real US dollar. There is nothing that can be shut down, and no centralized authority that needs to be trusted. Dai lives entirely within the Ethereum blockchain using smart contracts. *Features of Dai: 1. Dai is always worth $1 USD each 2. It can be freely traded like any other ERC20 token 3. Anyone with an Ethereum wallet can own, accept, and transfer it 4. It can be exchanged without any middleman 5. No individual person or company has control over it 6. No government or authority can shut it down *How Dai Works? Dai is a masterpiece of game theory that carefully balances economic incentives in the pursuit of one goal — a token that is continuously approaching the value of $1 USD. When Dai is worth above $1, mechanisms work to decrease the price. When Dai is worth below $1, mechanisms work to increase the price. The rational actors that take part in these mechanisms do so because they earn money anytime Dai is not perfectly worth $1. This is why Dai is always floating slightly above or below $1 — it is an endless wave function bouncing infinitely close to $1, but never quite achieving it. The farther Dai goes from $1, the more incentive there is to fix it. This is the magic of Dai. *How is Dai Created? Dai is simply a loan against Ethereum. By using the MakerDAO dApp, advanced users can take loans out in Dai against their ETH holdings. First, ETH is turned into “wrapped ETH” (WETH), which is simply an ERC20 wrapping around ETH. This “tokenizes” ETH so it can be used like any other ERC20 token. Next, WETH is turned into “pooled ETH” (PETH), which means it joins a large pool of Ethereum that is the collateral for all Dai created. Once you have PETH, you can create a “collateralized debt position” (CDP), which locks up your PETH and allows you to draw Dai against your collateral, which is PETH. As you draw out Dai, the ratio of debt in the CDP increases. There is a debt limit that sets a maximum amount of Dai you can draw against your CDP. Once you have Dai, you can spend or trade it freely like any other ERC20 token. *There are several important reasons why you would create Dai, despite the hassle: 1. You need a loan, and have an asset (ETH) to use as collateral for your loan 2. You believe ETH is going up in value. You can use your CDP to buy ETH on margin — you lock up your ETH in a CDP, draw Dai against it, use the Dai to buy more ETH on an exchange, and then use that ETH to further increase the size of your CDP. This can be accomplished without any third-party or centralized authority allowing you to do so — margin trading can be accomplished entirely on the blockchain. 3. The demand for Dai has driven the price above $1 USD. When this occurs, you can create Dai then immediately sell it on an exchange for greater than $1 USD. This is essentially free money, and is one of the mechanisms the Maker system uses to keep Dai pegged to $1 USD. Dai being worth over $1 USD encourages more Dai to be created. These three reasons are enough to ensure that Dai is continually created.