How dApps work?

Summary

In this discussion, the intricacies of decentralized applications (dApps) and their operation via blockchain technology are explored. The presenter contrasts traditional web apps, which rely on HTML, CSS, JavaScript, and databases, with decentralized apps that use blockchain for backend logic and data persistence. The essence of blockchain as a distributed ledger and its distinct features, like transaction chaining, decentralization, and tamper resistance, are explained. The process of connecting apps to blockchain through nodes or providers and signing transactions via crypto wallets like MetaMask is also delineated.

Highlights

• dApps replace traditional backend and databases with blockchain-ledger technology! 🚀
• Blockchain is a chain of blocks, where each block represents a transaction. 📦
• Decentralization of blockchain means data is stored across various nodes, not centralized servers. 🌍
• Connecting to blockchain is possible via personally operated nodes or third-party services like Infura or Quick Node. 🔌
• MetaMask helps in signing transactions, ensuring secure operations on the blockchain. 💼

Key Takeaways

• Decentralized apps (dApps) streamline backend execution and data storage using blockchain! 🌐
• Blockchain is not just a database; it's a distributed ledger maintaining transaction integrity and transparency. 🔗
• Blockchain's decentralized nature enhances security by spreading records across multiple nodes. 🛡️
• Nodes or providers are essential for connecting dApps to blockchain networks. 🖧
• MetaMask facilitates transaction signing using crypto wallet private keys, crucial for blockchain interactions. 🔐

Overview

Understanding decentralized applications (dApps) involves distinguishing them from conventional web applications. While traditional web apps use server-side logic and databases, dApps operate on blockchain technology where smart contracts execute backend logic, and data is stored on the blockchain ledger. This distinctive setup enhances data security and integrity due to blockchain’s decentralized nature.

Blockchain essentially functions as a distributed ledger, differing from typical databases by maintaining a decentralized, tamper-proof chain of transactions. Each transaction is recorded as a block, continuously appending to form a secure chain, hence the name blockchain. This setup distributes data across numerous nodes, unlike the central data storage seen in conventional systems, boosting security and reliability.

Connecting decentralized apps to the blockchain requires nodes, which serve as gateways to the blockchain network. Users can either run their own nodes or use services like Infura or Alchemy to facilitate connectivity. For transactions, tools like MetaMask, a crypto wallet browser plugin, are crucial for signing transactions securely, safeguarding private keys while enabling seamless blockchain interaction.

Chapters

• 00:00 - 00:30: Introduction to Blockchain Development The chapter discusses the growing popularity of blockchain development and highlights the key differences between conventional web applications and decentralized applications (dApps) that interact with a blockchain. It explains that conventional web apps consist of a front-end (often built using HTML, CSS, and JavaScript), a back-end (commonly using languages such as Node.js, Java, or Python), and a database for storing data like users, posts, comments, likes, etc.
• 00:30 - 01:00: Decentralized Application Architecture The chapter discusses the architecture of decentralized applications (dApps), focusing on the execution of app logic through smart contracts and data storage on blockchains. It highlights the final steps in achieving a fully decentralized application, particularly executing backend code and ensuring data persistence on the blockchain ledger. The chapter also poses an essential question on connecting apps to the blockchain for code execution and data storage, preluding a review of the foundational concept of a blockchain compared to conventional databases, which serve as a single source of truth.
• 01:00 - 01:30: Understanding Blockchain as a Ledger This chapter explains the concept of blockchain as a ledger. It compares blockchain to a traditional database but highlights key differences. Unlike a database, blockchain is a distributed ledger, which means it is not centralized. Instead, it records transactions completed by the network, thus ensuring a decentralized and transparent system. The chapter further elaborates on why the term "blockchain" is used, referring to the way transactions (blocks) are securely linked together (chain).
• 01:30 - 02:00: Functioning of Blockchain Nodes The chapter titled "Functioning of Blockchain Nodes" describes how each transaction in a blockchain is stored as a block, and new transactions are appended to form a chain of blocks. The blockchain is referred to as decentralized because its ledger isn't stored in a single location but is distributed across multiple nodes. These nodes play a critical role by validating transactions before they're added to the chain, with each node maintaining an identical record of all transactions.
• 02:00 - 02:30: Connecting Apps to the Blockchain The chapter 'Connecting Apps to the Blockchain' discusses how apps can access and interact with the blockchain. It explains the importance of connecting to a blockchain node to access or modify information. There are two ways to connect: running your own node or using third-party services like Infura, Alchemy, and QuickNode. The chapter highlights the preference and common practice of using third-party nodes due to their ease of use and reliability.
• 02:30 - 03:00: Using Providers and Wallets This chapter introduces the concepts of providers and wallets, which are essential for interacting with the blockchain. Providers enable connection to the blockchain, allowing users to read data. However, to write data or create transactions on the blockchain, transactions need to be signed with a crypto wallet's private key. Metamask, a browser-based crypto wallet plugin, is highlighted for storing private keys and facilitating transaction signing when needed.
• 03:00 - 03:30: Conclusion and Personal Reflection The chapter reflects on the initial challenges faced by the author when learning blockchain development, particularly around understanding the big picture and the term 'provider.' The author shares their personal experiences with using Metamask and hopes their insights will aid the reader in their own learning journey.

How dApps work? Transcription

• 00:00 - 00:30 blockchain development is becoming increasingly popular and today we're going to be talking about the main differences between a conventional web application and a decentralized app that are connected to the blockchain a conventional web app will have a front-end typically written in html css javascript that'll define the user interface then there's the back-end code which is typically written in node.js java or python that'll define the logic and finally there must be a place to store all the essential data such as users posts comments likes and so on which requires a database if we compare
• 00:30 - 01:00 a fully decentralized application will have the last two steps completed on the blockchain backend code that defines app logic will be executed by smart contracts while data that needs to be persisted will be stored on the blockchain ledger you might be asking how do we actually connect our app to the blockchain so we can run our app's codes and store information but before we get into that we need to remember what a blockchain is we know that a conventional database is a single source of information or truth if you want to
• 01:00 - 01:30 get data from a database you typically make a get request to the server or you'd make an api call to communicate to this single source now blockchain in the simplest terms is just a distributed ledger you can think of it almost like a distributed database except with a couple big differences first being that it's a ledger a ledger is a record of transactions completed by the network the reason it's called a blockchain is because each transaction
• 01:30 - 02:00 is represented as a block and every following transaction is appended to the previous block forming a chain the reason blockchain is often referred to as decentralized is because this ledger is not stored in a single place like typical databases or servers it's distributed amongst several nodes and these nodes are responsible for validating the transactions that will append the chain a node is where the blockchain lives because every node has an identical record of all transactions
• 02:00 - 02:30 it's nearly impossible to tamper modify or delete information on the blockchain so for us to allow our app to access information from the blockchain from the ledger or to make transactions append the ledger we need to be connected to a node there are two ways to do this you can either run and operate your own node or much preferably and most commonly use nodes provided by third-party services like infura alchemy and quick node just to name a few the nodes you connect with
• 02:30 - 03:00 when you need to interact with the blockchain are called providers once you connect to the blockchain through a provider you can read data stored on the blockchain but if you want to write data on the blockchain or create a transaction you'll need to sign the transaction using your crypto wallet's private key this signing of transaction is where metamask typically comes in metamask is a crypto wallet plugin for the browser that stores our private keys and whenever our frontend needs the user to sign a transaction it calls on
• 03:00 - 03:30 metamask and it pops up in the corner so i hope that clears up any confusion i remember when i first started doing blockchain tutorials on youtube and online i didn't necessarily understand how everything fit in together in a big picture kind of way and the word provider was kind of being thrown here and there without a proper explanation so i hope this helps you in your journey learning blockchain development