Blockchains:

1. Layer 1 Blockchains (Base Networks)
These are foundational blockchains that operate independently:
• Bitcoin – The first and most widely used cryptocurrency.
• Ethereum – Smart contract platform enabling decentralized applications (DApps).
• Solana – High-speed blockchain optimized for scalability.
• Polkadot – Multi-chain network enabling interoperability.
• Cardano – Research-driven blockchain with a focus on security and scalability.


2. Layer 2 Blockchains (Scaling Solutions)
These networks enhance Layer 1 blockchains by improving speed and reducing costs:
• Polygon – Ethereum scaling solution with fast transactions.
• Optimism – Layer 2 rollup for Ethereum, reducing gas fees.
• Arbitrum – Another Ethereum Layer 2 rollup improving efficiency.
• Lightning Network – Bitcoin’s Layer 2 solution for faster payments.


3. Layer 3 Blockchains (Application-Specific Networks)
These focus on specialized use cases:
• Oracles (Chainlink, Band Protocol) – Provide real-world data to smart contracts.
• Privacy Chains (Secret Network, Oasis Network) – Enhance blockchain privacy.
• Gaming Chains (Immutable X, Ronin) – Optimized for blockchain gaming.


4. Canary Networks (Experimental Blockchains)
These networks test new features before deployment:
• Kusama – Polkadot’s experimental network for testing innovations.
Ethereum Testnets
• Sepolia – Ethereum’s primary testnet.
• Goerli – Previously used for testing, now deprecated.
• Holesky – New Ethereum testnet replacing Goerli.
Polygon Testnets
• Amoy – Polygon’s latest testnet.
• Mumbai – Popular testnet for Polygon developers.
Binance Smart Chain (BSC) Testnets
• BSC Testnet – Binance’s official test network.
Solana Testnets
• Solana Devnet – Used for development and testing.
• Solana Testnet – Pre-mainnet testing environment.
Avalanche Testnets
• Fuji – Avalanche’s main testnet.
Polkadot & Kusama Testnets
• Westend – Polkadot’s testnet.
• Rococo – Used for parachain testing.
• Kusama – Canary network for Polkadot.
Optimism & Arbitrum Testnets
• Optimism Sepolia – Optimism’s testnet.
• Arbitrum Sepolia – Arbitrum’s testnet.
Other Notable Testnets
• SaharaAI Testnet – Experimental blockchain testnet.
• Berachain Bepolia – Testnet for Berachain.
• Mantle Sepolia – Mantle’s testnet.
• Celo Alfajores – Celo’s testnet.
• Base Sepolia – Base’s testnet.

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Blockchain Scan Sites These platforms allow users to explore blockchain transactions:

• Etherscan – Ethereum blockchain explorer.
• Polygonscan – Polygon blockchain explorer.
• BscScan – Binance Smart Chain explorer.
• Solscan – Solana blockchain explorer.
• SnowTrace – Avalanche blockchain explorer.

Testing & Auditing Software These tools help secure smart contracts:

• Slither – Static analysis tool for Solidity smart contracts.
• MythX – Security analysis service for Ethereum smart contracts.
• Quill Shield – AI-powered smart contract auditing.
• Manticore – Symbolic execution tool for smart contract security.

External Auditing & Security Sites These platforms analyze blockchain projects for security risks:

• TokenSniffer – Detects suspicious tokens.
• CoinGecko – Tracks cryptocurrency prices and market data.
• ScamSniper – Identifies potential crypto scams.
• Certik – Blockchain security auditing firm.

Other Useful Blockchain & Crypto Sites

• DappRadar – Tracks decentralized applications (DApps).
• DeFi Pulse – Monitors decentralized finance (DeFi) projects.
• NFTScan – NFT marketplace analytics.
• Messari – Crypto research and analytics.

Airdrop Sites These platforms list free token giveaways:

• AirDropAlert – Tracks upcoming crypto airdrops.
• Airdrops.io – Lists active and potential airdrops.
• Bankless Claimables – Checks wallet eligibility for airdrops.
• Earni.fi – Finds Ethereum-based airdrops.