What distinguishes a quantum computer from a conventional computer? What difficulties will need to be addressed for quantum computing to succeed?

What are the distinguishing characteristics between classical and quantum computers, and how do these two types of computing systems interact with each other? What are the obstacles that need to be overcome in order to achieve success in the field of quantum computing?

What are the key differences between a conventional computer and a quantum computer?What are the challenges that quantum computing faces?

What are the similarities and differences between classical and quantum computers, and how do they affect one another? To what extent do these obstacles need to be overcome before we can consider quantum computing a success story?