By Harini Priya K | LazAI Dev Ambassador
OOPS
A few weeks ago, I attended a Web3 workshop. Later, when I was randomly chatting with my senior, he asked me a simple question:
“Which layer does Sui belong to?”
I confidently replied, “It’s a Layer 1 blockchain.”
Then he followed up with another question:
“So, what’s the difference between Layer 1 and Layer 2?”
And that’s where I froze. 
I can code, I can work on projects, but in that moment, I realized I didn’t know how to explain the differences clearly. That experience pushed me to dig deeper into Web3 layers, and what I discovered is something every beginner should know.
So, in this blog, I’m sharing what I’ve learned ,explained in simple words, with examples and analogies ,so that the next time someone asks you about Layer 1 vs Layer 2 (and even Layer 0 & Layer 3), you’ll be ready with a confident answer.
Let’s break it down 
Layer 0 – The Roads & Bridges
What it is: Layer 0 is the foundation layer that lets multiple blockchains exist and connect with each other.
Problem: Without Layer 0, each blockchain is like an island, they don’t talk to each other.
Use case:
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Connect different blockchains
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Allow data and tokens to move across chains
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Provide infrastructure to build new blockchains
Analogy: Think of roads and bridges that connect different cities. Without them, each city is cut off.
Examples:
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Polkadot (connects blockchains through its Relay Chain)
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Cosmos (connects chains using IBC protocol)
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Avalanche Subnets (custom blockchains connected to Avalanche)
Layer 1 – The City
What it is: Layer 1 is the main blockchain itself where transactions happen and get recorded permanently.
Problem: When too many people use it, it gets slow and expensive (traffic jam).
Use case:
-
Record transactions securely
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Run smart contracts
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Host dApps directly
Analogy: It’s like a city where everyone lives and works. But if too many people rush at once, the streets get jammed.
Examples:
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Bitcoin (digital money)
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Ethereum (smart contracts & dApps)
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Solana (fast blockchain)
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Sui (Layer 1 blockchain)
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Cardano, Aptos, Algorand
Layer 2 – The Highways
What it is: Layer 2 sits on top of Layer 1 and helps it by making transactions faster and cheaper.
Problem: Layer 1 gets crowded → fees go up → transactions are slow.
Use case:
-
Move transactions off the main chain
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Reduce fees
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Improve speed while still using Layer 1’s security
Analogy: Think of highways built above the city. They take the pressure off crowded city roads and help people move faster.
Examples:
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Polygon (Ethereum scaling)
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Arbitrum (Optimistic Rollup)
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Optimism (Optimistic Rollup)
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zkSync, StarkNet (ZK Rollups)
Layer 3 – The Shops & Services
What it is: This is the application layer — the apps we actually use in Web3.
Problem: The challenge here is user experience — wallets, seed phrases, and onboarding can feel hard for beginners.
Use case:
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DeFi (finance without banks)
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NFTs (digital art, collectibles)
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Games (play-to-earn, metaverse)
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Social (decentralized social networks)
Analogy: Just like shops, restaurants, and services in a city make life useful, Layer 3 apps make blockchains useful for us.
Examples:
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Uniswap (DeFi trading)
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Aave (DeFi lending)
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OpenSea (NFT marketplace)
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Axie Infinity (Gaming)
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Lens Protocol (SocialFi)
Final Thought
I’m still a beginner in Web3, and sometimes the new words and concepts can be confusing. That’s okay! The important part is to understand the big picture.