Origins of “Turnkey”

turnkey

1650s, "jailer," from turn (v.) + key (n.). In reference to a job that only has to be done only once, it is recorded from 1934. The notion probably is of something that can be accomplished with a single turn of a key.

Its usage as 'complete and ready to use' is relatively recent.

The term turnkey is also often used in the technology industry, most commonly to describe pre-built computer "packages" in which everything needed to perform a certain type of task (e.g. audio editing) is put together by the supplier and sold as a bundle. This often includes a computer with pre-installed software, various types of hardware, and accessories. Such packages are commonly called appliances. A website with a ready-made solutions and some configurations is called a turnkey website.

Turnkey products are synonymous to "off-the-shelf" solutions and not customized.