Solana and Ethereum differ mainly in their architecture, scalability approach, transaction speed, and cost, even though both are popular platforms for building decentralised applications (dApps) and smart contracts.

Ethereum is the oldest and most widely adopted smart contract blockchain. It primarily uses a Proof of Stake (PoS) consensus mechanism and relies heavily on Layer 2 solutions, such as rollups, to improve scalability. While Ethereum is highly decentralised and secure, it often faces network congestion, leading to slower transaction speeds and higher gas fees during peak usage. Ethereum’s strong developer ecosystem and long track record make it a preferred choice for complex DeFi protocols, NFTs, and enterprise-grade applications.

Solana, on the other hand, is designed for high performance and speed. It combines Proof of Stake with an innovative mechanism called Proof of History (PoH), which timestamps transactions to improve efficiency. This allows Solana to process thousands of transactions per second with extremely low fees. Unlike Ethereum, Solana focuses on on-chain scaling rather than relying extensively on Layer 2 solutions.

Another key difference lies in programming and execution. Ethereum uses the Ethereum Virtual Machine (EVM) and Solidity, while Solana uses the Solana Virtual Machine (SVM) and supports Rust, enabling parallel transaction processing through its Sealevel engine.

In summary, Ethereum prioritises decentralisation and ecosystem maturity, while Solana emphasises speed, low costs, and scalability, making each suitable for different blockchain use cases.