What Are Mainframes, Mini-Computers, and Servers?
Years ago, it was easy to distinguish between mainframes, mini-computers, and server machines because they were different in physical size and computing power. Today, because of advances in technology reducing the physical size of computers yet increasing their power, it is much more difficult to make distinctions between these classes of machines. Originally, before the advent of mini-computers, servers, workstations, and personal computers, all computers were classified as mainframes. A mainframe was a large machine, often occupying a whole room. Because the hardware used to build mainframe computers heated up very quickly, mainframes were housed in a special glass enclosed, climate controlled rooms. Mainframe operating systems were very cryptic, and programming or administering a mainframe was a complicated affair. Initially, programmers wrote programs, often in languages like assembly language or COBOL, on punched cards. In later years, programmers and system administrators were ab
