What characterizes the client-server model?

The client-server model is characterized by a system wherein clients initiate requests for data or services, and servers respond to those requests. This model is foundational in networking and software architecture, facilitating communication where the client, typically a user's device or application, sends requests to a server, which is a more powerful machine often responsible for maintaining resources or services, such as databases or web pages.

In this context, the client-server architecture enables multiple clients to interact with the server simultaneously, making it efficient for managing resources and distributing workload. This interaction model allows for flexibility and scalability, where numerous clients can access the services offered by a single or multiple servers concurrently without limitations inherent in more rigid architectures.

Thus, the correct option effectively highlights the primary operational dynamic of the client-server architecture, marking it as an essential concept in understanding distributed computing and networking principles.