Church-Turing Thesis
Noun · Development
Definitions
The hypothesis that any function computable by an effective mechanical procedure can be computed by a Turing machine (or equivalently, by lambda calculus). Not a mathematical theorem but a thesis about the nature of computation. Has held for 90 years and defines the boundary of what computers can do.
In plain English: The idea that a Turing machine can compute anything that any reasonable computer can compute.
Example: "Quantum computers don't violate the Church-Turing thesis — they compute the same things, just faster for certain problems."