How does the memory of a real computer differ from the tape of a Turing machine?

The primary difference between the memory of a real computer and the tape of a Turing machine lies in their capacity.

A Turing machine is an idealized mathematical model that utilizes an infinitely extensible tape, allowing for an unlimited amount of storage space to perform computations. In contrast, a real digital computer possesses a finite amount of computer memory. While the Turing machine serves as the theoretical foundation for modern computing—mirroring the essential structure of an input/output device, memory, and a central processing unit—the physical constraints of actual hardware mean that a real computer cannot store an infinite sequence of symbols or process an infinite tape.1