A Turing machine is a theoretical device that helps us understand how computers process information. It consists of a tape divided into squares, which can hold symbols, and a head that reads and writes these symbols. The machine follows a set of rules to manipulate the symbols on the tape, allowing it to perform calculations and solve problems. Developed by the mathematician Alan Turing in the 1930s, this concept is fundamental to computer science. It provides a simple model for understanding computation and helps us explore what can be computed. The Turing machine is a key part of the theory behind modern computers and algorithms.