How dApps work?

Summary

This video explains the key differences between conventional web applications and decentralized applications (dApps) powered by blockchain. It highlights how traditional web apps have a front-end, back-end, and a centralized database, while dApps leverage smart contracts and the blockchain ledger for logic and data storage. The video also covers how dApps connect to the blockchain via nodes, either by running their own or using third-party services like Infura, and the importance of signing transactions securely with a crypto wallet like MetaMask. A great introduction to blockchain development for those new to the concept.

Takeaways

• 😀 Conventional web apps use front-end technologies like HTML, CSS, and JavaScript to define the user interface.
• 😀 Back-end logic in conventional web apps is usually written in languages like Node.js, Java, or Python, and relies on centralized databases.
• 😀 Decentralized apps (dApps) store business logic in smart contracts, which run on the blockchain, instead of traditional back-end servers.
• 😀 Data in decentralized apps is stored on the blockchain ledger, ensuring its security and immutability.
• 😀 Blockchain is a distributed ledger that records transactions in blocks, forming a chain, and is decentralized across multiple nodes.
• 😀 Unlike conventional databases, blockchain data is not stored in a single location, making it resistant to tampering and unauthorized changes.
• 😀 Nodes in the blockchain network validate transactions and maintain identical copies of the distributed ledger for every participant.
• 😀 To connect a dApp to the blockchain, developers can either run their own node or use third-party providers like Infura, Alchemy, or QuickNode.
• 😀 Third-party node providers simplify blockchain interaction by offering APIs to read and write data to the blockchain without running a node.
• 😀 Crypto wallets like MetaMask store private keys and allow users to sign transactions when interacting with the blockchain, adding a layer of security.
• 😀 Signing transactions with a wallet is crucial for dApps to write data to the blockchain or perform actions like executing smart contracts.

Q & A

What is the main difference between a conventional web application and a decentralized application (DApp)?

A conventional web application has a front-end for user interaction and a back-end for logic, with data stored in a traditional database. In contrast, a decentralized application (DApp) stores its back-end logic on the blockchain via smart contracts and stores data on the blockchain ledger.

What programming languages are typically used for the front-end and back-end of a conventional web app?

The front-end of a conventional web app is typically written in HTML, CSS, and JavaScript, while the back-end is usually written in Node.js, Java, or Python.

How does blockchain differ from a conventional database?

A blockchain is a decentralized, distributed ledger where transactions are stored in blocks that are linked in a chain. Unlike a conventional database, which stores data in a central location, blockchain data is distributed across nodes, making it tamper-resistant and immutable.

What is a node in the context of blockchain?

A node is a server or computer that holds a copy of the blockchain's entire ledger and validates transactions. Nodes maintain the blockchain by ensuring that transactions are correct and consistent across the network.

What does the term 'provider' mean in blockchain development?

A provider in blockchain development refers to a third-party service, such as Infura, Alchemy, or QuickNode, that offers access to blockchain nodes. Providers enable developers to interact with the blockchain without having to run their own nodes.

How can a developer connect to the blockchain to interact with the ledger?

A developer can connect to the blockchain by either running their own node or by using a third-party provider. The provider gives access to the blockchain, allowing the app to read data and send transactions to the ledger.

What is the role of smart contracts in decentralized applications?

Smart contracts are self-executing programs stored on the blockchain that define the logic of a DApp. They automatically execute predefined actions based on certain conditions, allowing decentralized applications to function without intermediaries.

Why is it necessary to sign transactions when interacting with the blockchain?

Signing transactions with a private key is necessary to ensure the security and authenticity of a transaction. It verifies that the sender is authorized to perform the transaction and prevents unauthorized access to the blockchain.

What is MetaMask and how does it help in blockchain development?

MetaMask is a browser plugin that functions as a cryptocurrency wallet. It stores private keys and allows users to sign transactions, enabling them to interact securely with decentralized applications (DApps) and the blockchain.

Can a DApp operate without using a third-party provider for blockchain access?

Technically, yes, a DApp can operate without a third-party provider if the developer sets up and maintains their own blockchain node. However, most developers prefer using third-party services for convenience, reliability, and scalability.