A computer system is the combination of hardware and software that allows us to perform various tasks on a computer. Hardware refers to the physical components of a computer such as the CPU, RAM, and hard drive. Software, on the other hand, refers to the programs and applications that run on the computer, like web browsers, video players, and games.

A computer network is a group of computers that are connected to each other, allowing the exchange of information and communication. Computer networks can be physical or virtual and can be used for various purposes such as sharing resources, communicating with others, and accessing information.