Minicomputer (colloquially, mini) is a largely obsolete term for a class of multi-user computers that lies in the midle range of the computing spectrum, in between the largest multi-user systems (mainframe computers) and the smallest single-user systems (microcomputers or personal computers). Formerly this class formed a distinct group with its own hardware and operating systems notably having smaller address space (notice the cited numbers of bits in a data word, ranging from 8 to 24 bits commonly around 16-bits). While the distinction between mainframe computers and smaller computers remains fairly clear, contemporary middle-range computers are not well differentiated from personal computers, being typically just a more powerful but still compatible version of a personal computer. More modern terms for minicomputer-type machines include midrange systems (IBM parlance), workstations (Sun Microsystems and general UNIX/Linux parlance), and servers.