In this talk I will discuss the concept of “quantum supremacy” and discuss where we stand with quantum computing now. I will start from Feynman's proposals of quantum computing and Landauer's principle of “information is physical”. Then I will talk about the building blocks of the quantum computer: qubits and quantum circuits, and the idea of universal quantum computer. I will introduce quantum algorithms that provide superpolynomial speedup and why then lead to quantum supremacy. Finally I will discuss the main obstacles to achieve quantum supremacy and where we stand now.~~