Sei is a Layer 1 blockchain specifically optimized for digital asset trading, launched in 2023 to solve scalability challenges in decentralized exchanges, NFT marketplaces, and gaming economies. This comprehensive guide explores Sei's technical architecture built on Cosmos SDK with Delegated Proof of Stake consensus, achieving sub-second transaction finality through its innovative Twin Turbo mechanism. As of 2026, Sei ranks among the top-100 cryptocurrencies with over 33 million holders and a market capitalization of $817.88 million, demonstrating significant ecosystem adoption. The article examines Sei's market performance, ecosystem applications spanning DeFi and GameFi, community engagement dynamics, and competitive positioning within the Layer 1 landscape. Key topics include token economics, on-chain metrics, strategic partnerships, and practical guidance for purchasing SEI on Gate exchange. Despite facing regulatory uncertainties and intense competition, Sei's specialized infrastructure and developer com