In the very beginnings of the computing revolution, decades before the invention of the microprocessor, a man named Alonzo Church did groundbreaking work in theoretical computer science. You may have heard of his student and collaborator, Alan Turing. Together, they created a theory of computable functions called the Church-Turing Thesis, which described the nature of computable functions.
…ring machine is frequently cited as the baseline of requirements for a modern programming language. A language or processor / VM instruction set is said to be turing complete if it can be used to simulate a universal turing machine. The first famous example of a turing-complete system was lambda calculus, described by Alonzo Church in 1936.