CoolCode - Solidity/Ethereum Blockchain Technology

16/04/2025

https://share.cryptozombies.io/ru/lesson/1/share/Anh?id=Y3p8NjQ4OTE1

I just completed CryptoZombies Lesson 1 and learned the basics of coding a game on Ethereum. Take a look at the first zombie in my army! Thanks .

25/03/2025

What is a transaction?

A transaction involves several steps when you're sending funds to someone. Here's how it works:

1. **Clicking "Send"**: When you click the send button, the webpage collects the recipient's address and sends it to an internal server.

2. **Node.js Backend**: This backend server, built using Node.js, handles the task of taking the address and transferring the funds.

3. **Web3 Library**: The server uses the Web3 library to create a transaction object. Here's what goes into that transaction:
- **Nonce**: The number of transactions sent by the sender.
- **To**: The recipient’s account address.
- **Value**: The amount of funds you wish to send.
- **Gas Price**: The price of gas for the transaction.
- **Gas Limit**: The maximum gas the transaction can consume.
- **v, r, s**: These are cryptographic elements of the transaction, including the sender's private key. Once signed, the transaction cannot be reversed, ensuring it’s legitimate.

4. **Final Step**: The backend server sends the transaction to the network via Web3, where it is broadcasted for processing.

Transactions ensure secure and legitimate transfers of funds within the blockchain ecosystem.

02/02/2025

Ethereum is a network of computers that enables money transfers and data storage. There are many different Ethereum networks, each supported by one or more nodes. A node is simply a machine running an Ethereum client.

What's important is that anyone can set up their own node, and each one holds a full and independent copy of the blockchain. The blockchain itself is like a database where every transaction, or transfer of funds between parties, is recorded.

These technologies make Ethereum unique and open to everyone! 🌐💸

24/01/2025

💡 In his 2008 White Paper, Satoshi Nakamoto outlined a revolutionary way for people to exchange value without relying on centralized entities—banks. Using blockchain technology, he proposed a decentralized payment system where individuals can send and receive money directly, without intermediaries. This vision marked the beginning of a new financial era, where control and freedom belong to the users, not institutions. 🚀

21/01/2025

A transaction on the Ethereum network is the process of transferring Ether (ETH) or interacting with smart contracts via the blockchain. It consists of several steps:

1. **Transaction Creation**: The user specifies the recipient’s address, transfer amount, contract data (if any), gas limit (Gas Limit), and gas price (Gas Price).

2. **Transaction Signing**: The transaction is signed with the sender's private key, confirming its authenticity.

3. **Sending to the Network**: The signed transaction is broadcast to the network, entering the mempool (transaction queue).

4. **Mining and Confirmation**: Miners include the transaction in a block, which is added to the blockchain. The transaction is considered confirmed when the block containing it receives several confirmations.

5. **Completion**: Once the transaction has enough confirmations, it becomes irreversible, and the balances of the sender and recipient are updated.

A transaction consists of the following elements:
- **Nonce** — a unique identifier for the transaction from a specific address.
- **Gas Price and Gas Limit** — the cost and limit of gas.
- **To** — the recipient's address (or smart contract address).
- **Value** — the amount of ETH to transfer.
- **Data** — data for interacting with a smart contract (if applicable).
- **Digital Signature** — confirms the authenticity of the transaction.

In summary, a transaction on Ethereum is a process that includes creation, signing, sending, and processing through the network, followed by confirmation on the blockchain.

27/12/2024

**What is Ethereum? A Simple Guide to the Network, Nodes, and Blockchain**

In recent years, Ethereum has become one of the most discussed technologies in the world of cryptocurrency and blockchain. But what exactly is it, and how does it work? Let’s break it down in simple terms.

# # # 1. Ethereum is a Network for Transferring Money and Storing Data

Think of Ethereum as a vast network of computers around the world working together to send money (or cryptocurrency) and store data. This network allows users to exchange value directly, without the need for intermediaries like banks. Everything happens peer-to-peer using blockchain technology.

# # # 2. There Are Many Different Ethereum Networks

Interestingly, there are several different Ethereum networks, each with slightly different features. However, they all share one common principle: they use technology to ensure the security and transparency of transactions and data processing.

# # # 3. What is a Node?

To understand how Ethereum works, you need to know what a node is. A node is simply a computer or server running an Ethereum client. Each node plays a role in maintaining the network’s functionality. The great thing is that anyone can run their own node, connect to the network, and participate in its operation.

# # # 4. Each Node Has a Copy of the Blockchain

Every node in the Ethereum network stores a complete copy of the blockchain. So, what exactly is the blockchain? The blockchain is essentially a huge database that stores records of all transactions that take place on the network. It’s like a public "ledger" that tracks who sent what amount of money, to whom, and when. Each node keeps track of updates and always has the most up-to-date information about the state of the entire network.

# # # 5. How Does the Blockchain Work?

You can think of the blockchain as a chain of blocks, where each block contains records of transactions. When someone sends money or performs another action, that information is recorded in a new block, which is then added to the chain. The great thing about blockchain is that all this data is public and accessible to all participants. This ensures that no one can alter the records later, making transactions transparent and secure.

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**So, to summarize:**

- Ethereum is a network for transferring money and storing data.
- There are many nodes in the network, and each one has a full copy of the blockchain.
- The blockchain is an open database that records all transactions.
- Anyone can become part of this network by running their own node.

If you want to learn more about how Ethereum works, or how you can use this technology for different purposes—feel free to ask questions or share your thoughts in the comments!

24/12/2024

On October 31, 2008, Satoshi Nakamoto released a White Paper describing how people could pay each other without using a central authority, such as a bank. Thanks to this paper, the Bitcoin network was launched in January 2009, with blockchain as its foundation. Blockchain is a tool for storing a list of financial transactions between different people. The sole purpose of Bitcoin is transactions.

Vitalik Buterin wrote his own official White Paper and published it at the end of 2013. He proposed using blockchain for more complex projects. He suggested using Ethereum to create sub-currencies, domain registration systems, and gaming applications. He described the concept of smart contracts. A smart contract is a piece of code that resides in the Ethereum blockchain. As a result, the Ethereum system was launched on July 30, 2015. Ethereum was created for smart contracts based on blockchain to enable the development of advanced applications.

10/12/2024

What is Blockchain?

Blockchain is a technology that stores data in a chain of blocks, each linked to the previous one. It’s a decentralized system, meaning there’s no need for intermediaries like banks or governments. All participants in the network can validate transactions, making the system transparent and secure against tampering.

Its applications go far beyond cryptocurrencies: blockchain is used in various sectors, from fintech to supply chain management and digital credentials.

07/01/2024