The main characteristic of a client-server architecture is its distributed computing model, where client devices request resources or services from centralized servers. In this framework, clients typically handle user interfaces and local processing tasks, while servers manage data storage, processing, and business logic. This separation allows for scalability, as multiple clients can connect to a single server, facilitating efficient resource utilization. Moreover, this architecture enhances maintainability and security by centralizing critical components, making it easier to implement updates and protect sensitive information.