A decentralized exchange (DEX) allows traders to buy and sell cryptocurrencies directly with each other on a peer-to-peer network without a central authority, enhancing security and trust. The document outlines various services offered by Mobiloitte, including development of DEX platforms with features like smart contract integration, high liquidity, and user-friendly interfaces. It emphasizes the company's expertise and successful project implementation in creating secure and efficient decentralized exchanges globally.