Douglas Harper's Etymology Dictionary
Wiktionary
n. 1 The joint ownership or lease of a property by multiple people who can only use it for specified periods each year. 2 (context computing English) A technique that allows many users to use a central computer simultaneously through remote terminals. vb. (present participle of time-share English)
Wikipedia
In computing, time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking at the same time.
Its introduction in the 1960s by students and professors at Dartmouth College, and emergence as the prominent model of computing in the 1970s, represented a major technological shift in the history of computing.
By allowing a large number of users to interact concurrently with a single computer, time-sharing dramatically lowered the cost of providing computing capability, made it possible for individuals and organizations to use a computer without owning one, and promoted the interactive use of computers and the development of new interactive applications.
Usage examples of "time-sharing".
In a time when more and more people in our society seem to be in need of psychiatric counseling, and when time-sharing of computers is widespread, I can even imagine the development of a network of computer psychotherapeutic terminals, something like arrays of large telephone booths, in which, for a few dollars a session, we are able to talk to an attentive, tested and largely nondirective psychotherapist.