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
nOS is a virtual operating system that introduces a new, decentralized internet. On this new internet user data is safe, and it only goes where the user wants it to go. nOS solves key issues surrounding dApp development, deployment, discovery, and interaction, allowing for true adoption of decentralized applications and blockchain technology. Because applications can choose to make their back-ends fully open-source and transparent, this new implementation of the World Wide Web is defined as the Open Internet. On nOS, applications and websites can be deployed in a completely open and decentralized manner by integrating smart contracts, client-side code, and public-key cryptography. Unlike server-side backend code, smart contracts can be open for all to read, allowing users to review how their data will be transmitted before any final commitments to action. Client-side code and other frontend materials can be distributed via nOS Filesystem, a decentralized file sharing protocol that allows for secure and transparent distribution of static files. By serving both backend logic and frontend material in an open-source, decentralized manner, true transparency between user and application can be achieved. dApps that are deployed to nOS can be accessed through nOS Client, a software solution for desktop and mobile that (among other features) introduces nOS Browser. nOS Browser functions as a web browser, with the added benefit that it integrates with the nOS Protocol, a blockchain-powered web protocol that facilitates secure and open accessibility of nOS dApps. The nOS Protocol resolves domain names that exist on nOS Name Service, a blockchain-powered decentralized implementation of a Domain Name Service, and allows for dApps to register domain names which are discoverable on nOS (e.g. mydapp.neo or my-dapp.eth). The dApp Gateway is a user-friendly dApp discovery platform (or “App Store”) where rankings are decided in a completely decentralized manner via Decentralized Authority. In order to achieve the features such as the ones described above, nOS is powered by the nOS Utility Token. The nOS Utility Token employs various staking and reward utilities which are intended for developers who wish to deploy and maintain dApps on nOS, and for end-users who wish to practice governance by Decentralized Authority. nOS eliminates the need for end-users to manually exchange crypto-currencies in order to make use of various dApps. By integrating crypto-currency exchange APIs, nOS Client automatically converts primary blockchain platform currencies (e.g. NEO/GAS for NEO, ETH for Ethereum) into the required amount of application tokens that are needed to make specific transactions or invocations.