Turing over his lifetime produced various groundbreaking seminal papers and works. In this write-up, I am going to delve into four such major works: "On Computable Numbers, with an Application to the Entscheidungsproblem" (1936); Bombe and Spider, Banburismus (1940–41); Computing Machinery and Intelligence (1950); Solvable and Unsolvable Problems (1954). David Hilbert and Wilhelm Ackermann discussed Entscheidungsproblem in their 1928 writing, The Principles of Mathematical Logic. They posed universal validity and satisfiability, which customarily was referred to as the decision problem (Hilbert et al., 1950). The decision problem can hence loosely be defined as coming up with an algorithm that takes an input and replies with a Yes or No depending on whether the statement is universally satisfiable.