A host system is generally the main (or central) computer in a networked computer system environment; that is, the computer to which other computers, terminals, or server computers are connected. In its most elementary state, a host system consists of two computer systems connected by modems and telephone lines. The system that contains the data is called the host (or "main" system), while the other system at which the user sits is called the remote terminal. A computer functioning as a host system becomes the beginning-point and end-point of data transfers with users working at remote locations accessing the host system at various times. The host computer provides services, such as news, mail, and data to computers that connect to it. The term "host system" is used in several contexts in addition to computer systems (such as devices, programs, and Web sites), each of which has...