The test proposed by Alan Turing for machine intelligence is the Turing test.
Turing introduced the idea in his 1950 paper “Computing Machinery and Intelligence,” published in the journal Mind. Rather than trying to define the difficult question “Can machines think?”, he proposed evaluating whether a machine could produce responses indistinguishable from those of a human in a text-based exchange.
A human judge communicates with unseen participants, including a computer, through written messages. If the judge cannot reliably identify which participant is the machine, the machine is said to have passed the test under the familiar modern interpretation. The test focuses on observable behaviour, not on proving that a machine possesses consciousness or human-like inner experience.
The main source of confusion is the phrase “imitation game.” That was Turing’s original term for the game he described, and the Turing test is commonly understood as a machine-focused adaptation of it. “Turing machine” is different: it is a mathematical model of computation, not an intelligence test. The Loebner Prize was a later competition inspired by the test.