Final answer:
A group of two or more computer systems linked by communications channels to share information is known as a computer network. Computer networks have transformed the global communication landscape since their inception in the 1960s and the public adoption of the Internet in the 1990s.
Step-by-step explanation:
A group of two or more computer systems linked together by communications channels to share data and information is called a computer network. This connectivity allows for data exchange and communication across distances, which has become a fundamental aspect of both personal and professional realms. With the rapid progress of technology since the 1960s, from the development of early networks by the Department of Defense to the mass public adoption of the Internet in the mid-1990s, the global landscape of communication has been transformed. Networks facilitated the creation of the World Wide Web, which hosts a vast array of contents, from text to multimedia, accessible through interconnected hypertext web pages.