An appchain is a specialized type of blockchain designed for a specific application. These appchains can be customized to accommodate the unique requirements of that specificDApp and nothing else. Depending on their design, appchains can be categorized into two main types: monolithic and modular blockchains. A monolithic appchain, such as Bitcoin, is designed as a single, self-contained blockchain that is solely dedicated to the function of the DApp it is intended for. For example, Bitcoin is specifically designed to function as a peer-to-peer electronic cash system. On the other hand, a modular appchain, such as dydx, is a blockchain that is designed to be modular in nature, allowing it to be more flexible and adaptable to the changing needs of the DApp it is intended for.