Which of the following is a computer that provides resources or services to other computers over a network?

A server is a computer designed specifically to provide resources, data, or services to other computers, known as clients, over a network. Servers manage network resources, handle requests, and ensure that clients have access to necessary files, applications, and services. This role is essential in network environments, as servers facilitate communication and resource sharing among multiple devices, streamlining processes for users.

In contrast, a host refers to any device connected to a network that can send or receive data, which includes both servers and clients. A client is a device that accesses services provided by a server but does not provide resources to other computers. A mainframe is a powerful computer primarily used by large organizations for bulk data processing and critical applications, but it does not inherently define the role of providing resources to other networked computers like a server does.