A Turing machine is a formal mathematical model of universal computation devised by Alan Turing in 1936. Comprising a linearly unbounded memory tape segregated into symbol cells, a bidirectional read/write head, and a finite state control register, it executes computations via a transition function δ. At every clock step, the machine scans the current tape symbol, writes a replacement character, transitions into a designated next internal state, and shifts the head left or right.