Web3

🔗 What is Web3?

Web3 is simply the next version of the internet — Web 3.0.
But instead of websites controlled by big companies like Google or Meta, Web3 gives power back to users.

How?
By letting users own their data and assets through something called a wallet, and running apps on blockchain networks instead of company servers.

Let’s unpack that step-by-step.

👛 What is a Wallet in Web3?

In Web3, your wallet is your identity.

Think of it as your:

• 🔐 Private vault (stores your private key)
• 💸 Digital bank (holds your tokens and NFTs)
• 🪪 Login ID (used to sign and verify who you are)

You don’t create an account. You create a wallet.
That wallet gives you a public key — your Web3 address — and a private key, which you must keep secret (it's how you prove ownership).

Some popular wallets:

• MetaMask (browser extension)
• Trust Wallet (mobile)
• Coinbase Wallet

A wallet can support multiple networks, and it usually uses one private key across all.
You can switch networks (Ethereum, Polygon, etc.) from inside the wallet.

📦 Where is Your Data Stored?

In Web2, your content and data are stored on company servers.
In Web3, it's stored on the blockchain — a public, tamper-proof system that anyone can verify but no one can secretly control.

So when you own a token or NFT, it’s not saved on some company’s database — it’s yours, recorded on a public ledger.

📕 What is the Blockchain?

A blockchain is a special kind of database, built like a growing notebook:

• 📖 Each page is a block
• 🔗 Pages are linked together — forever
• 🧾 It records everything: who sent what to whom, and when

This notebook (called a ledger) is shared across thousands of computers.
No one can cheat it. No one can erase it.

There are many blockchains — Bitcoin, Ethereum, Solana, etc.
Each one has its own ledger and its own token.

🧑‍💻 How Do You Join a Blockchain?

To join any blockchain network:

1. You create a wallet → it gives you a public/private key
2. Your public key = your address (like your username)
3. You can now send/receive tokens and interact with smart contracts

💰 What is a Token?

A token is digital value stored on the blockchain.
It can represent:

• Money (e.g., ETH, BTC)
• Digital assets (e.g., NFTs)
• Voting rights or access (e.g., governance tokens)

You can receive, hold, or trade them using your wallet.

🔍 How Bitcoin vs Ethereum Started

⚙️ How Blockchain Networks Work

Each blockchain runs on a consensus mechanism — it’s how everyone agrees on what's true.

The two main ones:

🪨 Proof of Work (PoW)

• Miners solve hard puzzles using powerful computers
• First one to solve it adds a new block
• Example: Bitcoin

🪙 Proof of Stake (PoS)

• Validators stake their tokens as collateral
• If they behave, they earn rewards
• If they cheat, part of their stake is destroyed ("slashed")
• Example: Ethereum, Polygon, Solana

Validators are often companies (like Coinbase or Binance), but any user can stake tokens through them and earn a cut of the rewards.

⚒️ What is a Smart Contract?

A smart contract is a program stored on the blockchain that runs automatically when triggered.

Think of it like a vending machine:

• You insert money (send tokens)
• It checks the amount
• If correct, it gives you what you paid for (e.g. NFT, reward, access)

✅ No human needed
✅ No middleman
✅ Always runs the same way

Smart contracts are written in Solidity (a programming language similar to JavaScript) and once deployed, they can’t be changed.

💻 What Can Developers Build?

Ethereum (and similar chains) let developers build decentralized apps — called dApps.

Apps like:

• NFT marketplaces (e.g. OpenSea)
• Token swaps (e.g. Uniswap)
• Staking dashboards
• Voting platforms (DAOs)

These apps are public, permissionless, and don’t need central servers to run.

🔐 What is Staking?

Staking means locking your tokens to help secure a Proof-of-Stake blockchain.

Here’s how it works:

1. You stake your tokens in a smart contract
2. A validator includes them in their block
3. If they act honestly, they earn rewards
4. You earn a share of those rewards

It’s like earning interest while helping the network run.

🏗️ Anatomy of a Web3 App

Here’s how a basic Web3 dApp is built:

User Wallet ──signs tx──▶ Frontend (React + wagmi / ethers / viem)
         │                     │
         ▼                     ▼
     Blockchain Node ◀──▶ Smart Contract (Solidity)

Optional tools:

• The Graph → for fast data querying
• Infura / Alchemy → access blockchain nodes
• IPFS → store files off-chain

🔌 What is JSON-RPC?

Web3 frontends talk to blockchain nodes using JSON-RPC — a simple messaging protocol.

Example:

{
  "method": "eth_getBalance",
  "params": ["0xYourAddress", "latest"]
}

Libraries like ethers.js, wagmi, and viem handle this under the hood.

🧰 Popular Web3 Frontend Libraries

Most modern Web3 React apps use:
React + wagmi + viem

🧱 What’s Holding Web3 Back?

Web3 is early. It works, but it’s not smooth yet.
Here’s what still needs improvement:

• 🐢 Speed & fees (scalability)
• 🧩 Onboarding (wallets & gas are confusing)
• 🛠️ Tools (still maturing)

🔮 The Vision of Web3

Imagine this:

• You log into apps with just your wallet — no email, no password
• You post on social media — and own your content
• You shop online — and pay with crypto or stablecoins
• You earn, spend, and build — with no one in the middle

That’s the promise of Web3.

And now, as a developer, you understand the foundation to help build it.