What is Ethereum?

Ethereum is a decentralized platform that allows people to build and run smart contracts and decentralized applications (DApps). It was created to provide a way for developers to create and execute programs on a global network of computers called the Ethereum Virtual Machine (EVM).

At its core, Ethereum is based on blockchain technology, just like Bitcoin. But while Bitcoin focuses mainly on being a digital currency, Ethereum expands on that idea by enabling the development of a wide range of applications beyond money.

The main concept in Ethereum is the smart contract. A smart contract is like a digital agreement that automatically executes when certain conditions are met. It's called "smart" because it can self-execute without the need for intermediaries like banks or lawyers. Smart contracts are written in a programming language called Solidity.

Ethereum's blockchain is a decentralized ledger that records all transactions and smart contracts. It's maintained by a network of computers, or nodes, around the world. These nodes work together to validate and store the data, ensuring that it remains secure and tamper-proof.

The Ethereum platform has its own cryptocurrency called Ether (ETH). Ether is used to power the network and incentivize the nodes to perform computations and validate transactions. It's also used to pay for gas, which is the computational power required to execute operations on the Ethereum network. Gas helps prevent spam and abuse on the network.

One of the significant advantages of Ethereum is its ability to support decentralized applications. DApps are like traditional apps, but instead of relying on a centralized server, they run on the Ethereum blockchain. This means they are resistant to censorship and single points of failure. DApps can be anything from decentralized finance (DeFi) platforms and games to supply chain management systems and prediction markets.

Ethereum is constantly evolving, and upgrades like Ethereum 2.0 aim to address scalability and improve the network's efficiency. The upgrade will transition Ethereum from a proof-of-work (PoW) consensus mechanism to a proof-of-stake (PoS) mechanism, which is expected to make the network faster and more energy-efficient.

Compared to Bitcoin

Many people entering the world of cryptocurrencies often start with Bitcoin. However, Ethereum stands out with its distinctive features and purpose. we'll explore the ways in which Ethereum differs from Bitcoin and why it has gained significant attention and adoption in the blockchain space.

1. Purpose: Beyond Digital Currency:
While Bitcoin is primarily known as a decentralized digital currency, Ethereum goes beyond that. Ethereum serves as a platform for decentralized applications (DApps) and smart contracts. It acts as a world computer, allowing developers to create and execute complex applications and agreements directly on the blockchain.

2. Construction: A Programmable Blockchain:
Bitcoin's scripting language is limited, mainly focusing on simple spending conditions. In contrast, Ethereum is built as a general-purpose programmable blockchain. It incorporates a virtual machine capable of executing code of any complexity, making it Turing complete. This means Ethereum can function as a versatile and powerful computer network.

3. Smart Contracts: Enabling Automation and Agreements:
One of Ethereum's key differentiators is the concept of smart contracts. These self-executing agreements automatically execute when specific conditions are met. With Ethereum's programming capabilities, developers can create sophisticated smart contracts that automate various processes, from financial transactions to supply chain management.

4. Ether as a Utility Currency:
While Bitcoin serves as a digital currency and a store of value, Ethereum's native currency, called ether (ETH), plays a different role. Ether acts as a utility currency within the Ethereum ecosystem, used to pay for computational resources and transactions on the platform. It fuels the execution of smart contracts and incentivizes participants to secure the network.

5. Development Community and Ecosystem:
Bitcoin has a strong focus on financial use cases, while Ethereum attracts a broader range of developers and projects due to its programmability. Ethereum has become a hub for decentralized finance (DeFi), gaming, non-fungible tokens (NFTs), and more. Its thriving ecosystem offers a multitude of decentralized applications and innovative projects.

Components of Blockchain

The components of an open, public blockchain are (usually):

1. Peer-to-Peer Network: Connecting Participants:
An open blockchain relies on a peer-to-peer (P2P) network, enabling direct communication and interaction between participants. This decentralized network propagates transactions and blocks of verified transactions across the network, ensuring that all participants have access to the latest information.

2. Transactions: Representing State Transitions:
Transactions are the messages within the blockchain network that represent state transitions. These transactions encapsulate information such as the sender, recipient, and any associated data. They play a crucial role in updating the state of the blockchain and initiating changes in the system.

3. Consensus Rules: Governing Validity:
Consensus rules define what constitutes a valid transaction and determine the conditions for a valid state transition. These rules ensure that all participants in the blockchain network agree on the correctness and validity of transactions and prevent malicious activities.

4. State Machine: Processing Transactions:
The state machine is a fundamental component that processes transactions based on the consensus rules. It executes the logic encoded within smart contracts or protocols to update the state of the blockchain. This processing step is crucial in maintaining the integrity and accuracy of the blockchain.

5. Cryptographically Secured Blocks: The Journal of State Transitions:
Blocks serve as a journal of all verified and accepted state transitions in the blockchain. Each block contains a set of transactions, along with additional information such as a timestamp and a reference to the previous block. These blocks are cryptographically secured, ensuring immutability and tamper resistance.

6. Consensus Algorithm: Decentralized Control:
Consensus algorithms are designed to decentralize control over the blockchain network. They require participants to collaborate and agree on the validity of transactions and state transitions. Through mechanisms like proof-of-work or proof-of-stake, consensus algorithms enable the network to reach a collective agreement without relying on a centralized authority.

7. Incentivization Scheme: Economically Securing the State Machine:
To secure the state machine and incentivize participants, open blockchains often employ game-theoretically sound schemes. For example, proof-of-work involves participants competing to solve complex mathematical puzzles, with rewards given to successful miners. This incentivization scheme ensures the economic stability and security of the blockchain network.

8. Open Source Software Implementations:
Open blockchains often have one or more open source software implementations, known as "clients." These clients provide the necessary tools for participants to interact with the blockchain network, including wallet software, node software, and development frameworks.

Most blockchains combine multiple components into a single software client. For example, Bitcoin Core is the reference implementation for Bitcoin, while Ethereum has a reference specification called the Yellow Paper, with multiple clients built according to this specification.

The components of a blockchain include the peer-to-peer network, transactions, consensus rules, state machine, cryptographically secured blocks, consensus algorithm, incentivization scheme, and open source software implementations. These components work together to create a decentralized and transparent system.

As the blockchain landscape has evolved, it has become essential to use qualifiers to understand the characteristics of a particular blockchain system. Qualifiers such as open, public, global, decentralized, neutral, and censorship-resistant help identify the important emergent characteristics of a blockchain.

Today, there is a wide variety of blockchains, each with different properties and characteristics. It is crucial to ask questions and seek clarification when someone mentions a "blockchain." Asking for a description of the components and inquiring whether the blockchain exhibits qualities like being open, public, etc., helps to understand its nature.

Birth of Ethereum

Ethereum emerged as a solution to extend the capabilities of Bitcoin and address the need for more flexibility and freedom in blockchain applications. we'll explore the journey of Ethereum's conception, the challenges faced by developers, and how Ethereum's founders pioneered a general-purpose blockchain to revolutionize decentralized applications.

1. The Need for Innovation:
Recognizing the potential beyond cryptocurrency, developers sought to go beyond the limitations of the Bitcoin model. However, building on Bitcoin required workarounds due to its intentional constraints. The constraints on transaction types, data types, and data storage hindered the development of diverse applications directly on the Bitcoin blockchain.

2. Vitalik Buterin's Proposal:
In 2013, Vitalik Buterin, a young programmer and Bitcoin enthusiast, began envisioning a more versatile blockchain. He proposed the idea of a Turing-complete, general-purpose blockchain to the Mastercoin team. While the proposal was too radical for their development roadmap, it gained attention and feedback from a small group of individuals.

3. Collaboration and Refinement:
Vitalik shared an early draft of the Ethereum whitepaper, receiving input and suggestions from a few dozen people. Notable contributors included Andreas M. Antonopoulos, who showed interest in Ethereum's potential but focused on writing his book at the time. Dr. Gavin Wood, a skilled C++ programmer, joined forces with Vitalik and became Ethereum's co-founder, codesigner, and CTO.

4. The Birth of Ethereum:
From December 2013 onward, Vitalik and Gavin collaborated to refine and evolve the Ethereum concept. They constructed the protocol layer that would become Ethereum, envisioning a blockchain that could support a wide range of applications through programmability. Their goal was to abstract the complexities of peer-to-peer networks, blockchains, and consensus algorithms, providing a secure and deterministic environment for decentralized applications.

5. Combining Innovations:
Similar to Satoshi Nakamoto, the creator of Bitcoin, Vitalik and Gavin combined existing technologies with new inventions to demonstrate their vision. They meticulously developed and refined the Ethereum platform over the years, culminating in the mining of the first Ethereum block on July 30, 2015.

Ethereum's Four Stages Development

Ethereum’s development was planned over four distinct stages, with major changes occurring at each stage. A stage may include subreleases, known as "hard forks," that change functionality in a way that is not backward compatible.

The four main development stages are codenamed Frontier, Homestead, Metropolis, and Serenity. The intermediate hard forks that have occurred to date are codenamed Ice Age, DAO, Tangerine Whistle, Spurious Dragon, Byzantium, Constantinople/St. Petersburg, Istanbul and Muir Glacier. Both the development stages and the intermediate hard forks are shown on the following timeline, which is "dated" by block number:

1. Frontier:
Frontier was the initial stage of Ethereum, commencing on July 30, 2015, and lasting until March 2016. It marked the launch of the Ethereum blockchain, allowing developers and users to engage with the network and experiment with decentralized applications.

2. Homestead:
Homestead, launched in March 2016, represented the second stage of Ethereum. It introduced improvements to enhance the stability and security of the platform, solidifying Ethereum as a reliable ecosystem for decentralized applications.

3. Metropolis:
Metropolis, the third stage of Ethereum, was divided into two hard forks: Byzantium and Constantinople/St. Petersburg. Byzantium, implemented in October 2017 at block #4,370,000, introduced low-level functionalities and adjusted the block reward and difficulty. Constantinople/St. Petersburg, initially planned as the second part of Metropolis, underwent a last-minute postponement due to a critical bug discovery and was eventually renamed St. Petersburg.

4. Serenity:
Serenity represents the final stage of Ethereum's development, often referred to as "Ethereum 2.0." It involves a comprehensive overhaul of Ethereum's infrastructure to address scalability, security, and sustainability. Serenity will introduce significant changes, including the transition from proof-of-work (PoW) to proof-of-stake (PoS) consensus, shard chains for improved scalability, and other enhancements.

Ethereum has successfully completed the Berlin and London hard forks, marking significant milestones in its development. These upgrades have brought notable improvements to the Ethereum network, paving the way for the final stage of development known as Serenity or Ethereum 2.0.

• Berlin: Advancing Ethereum's Capabilities
  The Berlin hard fork, already implemented, brought important enhancements to Ethereum. It focused on optimizing the platform's functionality by introducing several Ethereum Improvement Proposals (EIPs). These EIPs aimed to improve the efficiency of smart contract execution, enhance transaction processing, and streamline overall network performance. With Berlin, Ethereum took a significant step forward in preparing the foundation for Ethereum 2.0.

• London: Revolutionizing Transaction Fees
  The London hard fork is the next milestone on Ethereum's roadmap. It introduces a groundbreaking change to the transaction fee structure through the implementation of EIP-1559. This upgrade aims to improve the user experience by introducing a more predictable fee mechanism and reducing transaction costs. Additionally, EIP-3554 will adjust the mining reward structure, further enhancing the network's sustainability. London is expected to be deployed in the coming months, bringing important improvements to Ethereum's fee model.

Ethereum's Components

In Ethereum, the key components of a blockchain system are:

1. P2P network: Ethereum operates on a network called the Ethereum main network, which enables peer-to-peer communication among participants.

2. Consensus rules: The rules that govern how Ethereum operates are defined in the Yellow Paper, a reference specification for the platform.

3. Transactions: Ethereum transactions are messages exchanged on the network and include information such as the sender, recipient, value, and data payload.

4. State machine: Ethereum uses the Ethereum Virtual Machine (EVM), a virtual machine that executes smart contracts written in high-level languages like Solidity. These contracts are compiled into bytecode for execution on the EVM.

5. Data structures: Ethereum's state is stored in a database, typically LevelDB, on each node. The data is organized using a Merkle Patricia Tree, a hashed data structure.

6. Consensus algorithm: Currently, Ethereum uses Nakamoto Consensus, the same model as Bitcoin, where blocks are created through proof-of-work (PoW). However, there are plans to transition to a proof-of-stake (PoS) system called Casper in the future.

7. Economic security: Ethereum currently relies on the Ethash PoW algorithm for security. However, as the platform moves towards PoS, this algorithm will be replaced.

8. Clients: Ethereum has multiple client software implementations, including Go-Ethereum (Geth) and Parity, which enable interaction with the Ethereum network.

These components work together to power Ethereum's decentralized and programmable blockchain platform, facilitating the execution of smart contracts and the secure transfer of digital assets.

Ethereum Basics

Ethereum’s currency unit is called ether, identified also as "ETH" or with the symbols Ξ (from the Greek letter "Xi" that looks like a stylized capital E) or, less often, ♦: for example, 1 ether, or 1 ETH, or Ξ1, or ♦1.

Ether is subdivided into smaller units, down to the smallest unit possible, which is named wei. One ether is 1 quintillion wei (1 * 1018 or 1,000,000,000,000,000,000). You may hear people refer to the currency "Ethereum" too, but this is a common beginner’s mistake. Ethereum is the system, ether is the currency.

The value of ether is always represented internally in Ethereum as an unsigned integer value denominated in wei. When you transact 1 ether, the transaction encodes 1000000000000000000 wei as the value.

Choosing an Ethereum Wallet

The term "wallet" has come to mean many things, although they are all related and on a day-to-day basis boil down to pretty much the same thing. We will use the term "wallet" to mean a software application that helps you manage your Ethereum account. In short, an Ethereum wallet is your gateway to the Ethereum system. It holds your keys and can create and broadcast transactions on your behalf. Choosing an Ethereum wallet can be difficult because there are many different options with different features and designs. Some are more suitable for beginners and some are more suitable for experts. The Ethereum platform itself is still being improved, and the "best" wallets are often the ones that adapt to the changes that come with the platform upgrades.

But don’t worry! If you choose a wallet and don’t like how it works—or if you like it at first but later want to try something else—you can change wallets quite easily. All you have to do is make a transaction that sends your funds from the old wallet to the new wallet, or export your private keys and import them into the new one.

The following are some good starter wallets:

1. MetaMask
MetaMask is a browser extension wallet that runs in your browser (Chrome, Firefox, Opera, or Brave Browser). It is easy to use and convenient for testing, as it is able to connect to a variety of Ethereum nodes and test blockchains. MetaMask is a web-based wallet that also includes mobile apps for both iOS and Android.

2. Jaxx
Jaxx is a multiplatform and multicurrency wallet that runs on a variety of operating systems, including Android, iOS, Windows, macOS, and Linux. It is often a good choice for new users as it is designed for simplicity and ease of use. Jaxx is either a mobile or a desktop wallet, depending on where you install it.

3. MyEtherWallet (MEW)
MyEtherWallet is primarily a web-based wallet that runs in any browser. It is also available on Android and iOS. It has multiple sophisticated features we will explore in many of our examples.

4. Emerald Wallet
Emerald Wallet is designed to work with the Ethereum Classic blockchain, but is compatible with other Ethereum-based blockchains. It’s an open source desktop application and works under Windows, macOS, and Linux. Emerald Wallet can run a full node or connect to a public remote node, working in a "light" mode. It also has a companion tool to do all operations from the command line.

Why Learn Ethereum?

Blockchains have a very steep learning curve, as they combine multiple disciplines into one domain: programming, information security, cryptography, economics, distributed systems, peer-to-peer networks, etc. Ethereum makes this learning curve a lot less steep, so you can get started quickly. But just below the surface of a deceptively simple environment lies a lot more. As you learn and start looking deeper, there’s always another layer of complexity and wonder.

Ethereum is a great platform for learning about blockchains and it’s building a massive community of developers, faster than any other blockchain platform. More than any other, Ethereum is a developer’s blockchain, built by developers for developers. A developer familiar with JavaScript applications can drop into Ethereum and start producing working code very quickly. For the first few years of Ethereum’s life, it was common to see T-shirts announcing that you can create a token in just five lines of code. Of course, this is a double-edged sword. It’s easy to write code, but it’s very hard to write good and secure code.

"Jump into Ethereum's world of infinite possibilities, where understanding smart contracts is as easy as explaining quantum mechanics to a goldfish✨😅"