Ethereum enables developers to build and deploy decentralized applications. A decentralized application or Dapp serve some particular purpose to its users. Bitcoin, for example, is a Dapp that provides its users with a peer to peer electronic cash system that enables online Bitcoin payments. Because decentralized applications are made up of code that runs on a blockchain network, they are not controlled by any individual or central entity.
Both blockchains have the same features and are identical in every way up to a certain block where the hard-fork was implemented. This means that everything that happened on Ethereum up until the hard-fork is still valid on the Ethereum Classic Blockchain. From the block where the hard fork or change in code was executed onwards, the two blockchains act individually.

Nigel Dodd argues in The Social Life of Bitcoin that the essence of the bitcoin ideology is to remove money from social, as well as governmental, control.[131] Dodd quotes a YouTube video, with Roger Ver, Jeff Berwick, Charlie Shrem, Andreas Antonopoulos, Gavin Wood, Trace Meyer and other proponents of bitcoin reading The Declaration of Bitcoin's Independence. The declaration includes a message of crypto-anarchism with the words: "Bitcoin is inherently anti-establishment, anti-system, and anti-state. Bitcoin undermines governments and disrupts institutions because bitcoin is fundamentally humanitarian."[131][130]
Every 2,016 blocks (approximately 14 days at roughly 10 min per block), the difficulty target is adjusted based on the network's recent performance, with the aim of keeping the average time between new blocks at ten minutes. In this way the system automatically adapts to the total amount of mining power on the network.[7]:ch. 8 Between 1 March 2014 and 1 March 2015, the average number of nonces miners had to try before creating a new block increased from 16.4 quintillion to 200.5 quintillion.[86]
Both blockchains have the same features and are identical in every way up to a certain block where the hard-fork was implemented. This means that everything that happened on Ethereum up until the hard-fork is still valid on the Ethereum Classic Blockchain. From the block where the hard fork or change in code was executed onwards, the two blockchains act individually.
Network nodes can validate transactions, add them to their copy of the ledger, and then broadcast these ledger additions to other nodes. To achieve independent verification of the chain of ownership each network node stores its own copy of the blockchain.[76] About every 10 minutes, a new group of accepted transactions, called a block, is created, added to the blockchain, and quickly published to all nodes, without requiring central oversight. This allows bitcoin software to determine when a particular bitcoin was spent, which is needed to prevent double-spending. A conventional ledger records the transfers of actual bills or promissory notes that exist apart from it, but the blockchain is the only place that bitcoins can be said to exist in the form of unspent outputs of transactions.[7]:ch. 5
بيتكوين (بالإنجليزية: Bitcoin) هي عملة معماة ونظام دفع عالمي يمكن مقارنتها بالعملات الأخرى مثل الدولار أو اليورو، لكن مع عدة فوارق أساسية، من أبرزها أن هذه العملة هي عملة إلكترونية بشكل كامل تتداول عبر الإنترنت فقط من دون وجود فيزيائي لها.[1] وهي أول عملة رقمية لامركزية - فهي نظام يعمل دون مستودع مركزي أو مدير واحد، أي أنها تختلف عن العملات التقليدية بعدم وجود هيئة تنظيمية مركزية تقف خلفها. وتتم المعاملات بشبكة الند للند بين المستخدمين مباشرة دون وسيط من خلال استخدام التشفير. يتم التحقق من هذه المعاملات عن طريق عُقد الشبكة وتسجيلها في دفتر حسابات موزع وعام يسمى سلسلة الكتل. اخترع البيتكوين شخص غير معروف أو مجموعة من الناس عرف باسم ساتوشي ناكاموتو وأُصدِر كبرنامج مفتوح المصدر في عام 2009.
The "Metropolis Part 1: Byzantium" soft[citation needed] fork took effect on 16 October 2017, and included changes to reduce the complexity of the EVM and provide more flexibility for smart contract developers. Byzantium also added supports for zk-SNARKs (from Zcash), with the first zk-SNARK transaction occurring on testnet on September 19, 2017.[citation needed]
To lower the costs, bitcoin miners have set up in places like Iceland where geothermal energy is cheap and cooling Arctic air is free.[205] Bitcoin miners are known to use hydroelectric power in Tibet, Quebec, Washington (state), and Austria to reduce electricity costs.[204][206] Miners are attracted to suppliers such as Hydro Quebec that have energy surpluses.[207] According to a University of Cambridge study, much of bitcoin mining is done in China, where electricity is subsidized by the government.[208][209]
Because of bitcoin's decentralized nature and its trading on online exchanges located in many countries, regulation of bitcoin has been difficult. However, the use of bitcoin can be criminalized, and shutting down exchanges and the peer-to-peer economy in a given country would constitute a de facto ban.[167] The legal status of bitcoin varies substantially from country to country and is still undefined or changing in many of them. Regulations and bans that apply to bitcoin probably extend to similar cryptocurrency systems.[168]
نيمكوين : مليون هو مجموع عملة ال نيمكوين وهذا يعني أن ال نيمكوين ستكون نادرة نسبيا، بالضبط نفس مستوى ندرة ال بيتكوين . هذا وتساعد ال نيمكوين على إنشاء الإنترنت الغير خاضعة للرقابة، وتنكر السيطرة الحكومية. وهي منصة متعددة الاستخدامات يمكن استخدامها لنظام أسماء النطاقات الغير مركزي والغير منظم، نوع من الإنترنت الخاصة بها. ويمكن أيضا أن تستخدم لإرسال الرسائل، والتصويت، ونظام تسجيل الدخول.
The proof-of-work system, alongside the chaining of blocks, makes modifications of the blockchain extremely hard, as an attacker must modify all subsequent blocks in order for the modifications of one block to be accepted.[87] As new blocks are mined all the time, the difficulty of modifying a block increases as time passes and the number of subsequent blocks (also called confirmations of the given block) increases.[75]
Physical wallets store the credentials necessary to spend bitcoins offline and can be as simple as a paper printout of the private key;[7]:ch. 10 a paper wallet. A paper wallet is created with a keypair generated on a computer with no internet connection; the private key is written or printed onto the paper[g] and then erased from the computer. The paper wallet can then be stored in a safe physical location for later retrieval. Bitcoins stored using a paper wallet are said to be in cold storage.[99]:39 In a 2014 interview, QuadrigaCX founder Gerald Cotten explained that the company stored customer funds on paper wallets in safe deposit boxes: "So we just send money to them, we don’t need to go back to the bank every time we want to put money into it. We just send money from our Bitcoin app directly to those paper wallets, and keep it safe that way."[100]
A wallet stores the information necessary to transact bitcoins. While wallets are often described as a place to hold[93] or store bitcoins, due to the nature of the system, bitcoins are inseparable from the blockchain transaction ledger. A wallet is more correctly defined as something that "stores the digital credentials for your bitcoin holdings" and allows one to access (and spend) them.[7]:ch. 1, glossary Bitcoin uses public-key cryptography, in which two cryptographic keys, one public and one private, are generated.[94] At its most basic, a wallet is a collection of these keys. 

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