1) Quantum computing harnesses the laws of quantum mechanics to solve complex problems faster than classical computers. It uses quantum bits (qubits) that can exist in superpositions of states and become entangled in ways that normal computing cannot achieve.
2) Machine learning is a type of artificial intelligence that allows systems to learn from data and improve their abilities. Quantum machine learning combines quantum computing and machine learning to potentially solve problems like pattern recognition and optimization much faster.
3) Some challenges to quantum computing include qubit decoherence, error correction, scalability, and developing hardware and software. However, quantum computing shows promise for applications in fields like artificial intelligence, machine learning, cybersecurity, materials science, and pharmaceutical research