A computer system is composed of various hardware components like the central processing unit (CPU), memory, storage devices, and input/output devices such as keyboard and mouse. The software layer on top of this hardware provides an interface for users to interact with the computer system and perform various tasks.

A computer network is a set of interconnected devices that are used to share resources and communicate with each other. There are different types of computer networks like Local Area Networks (LANs), Wide Area Networks (WANs), and the internet. Computer networks facilitate various applications like email, online gaming, e-commerce, and video conferencing. The network infrastructure includes routers, switches, hubs, and other networking hardware, as well as software technologies like protocols and services that enable communication and data exchange between devices on the network.