A classical computer is not a quantum computer. Quantum computer depends on *non classical model* for computing. In a quantum computer where quantum mechanical concepts and phenomenon like superposition and entanglement has been used. Things are very useful for operations with data. For a classical computer classical models like *Turning machine* and *Lambada calculus *has been used. Classical representation of computational memory has been focused. Binary computing is the basic of classical computing where quantum computing represents data in quantum bits. There is ON and OFF state in a classical bits whereas QUBIT has both ON and OFF at the same time due to a condition known superposition.