The primary concept of quantum mechanics is that matter and energy exhibit both particle and wave properties. This duality means that the behavior of subatomic particles cannot be precisely predicted and is often described in terms of probabilities rather than deterministic views. Quantum mechanics explores phenomena at the atomic and molecular level, leading to insights like superposition and entanglement. This framework has profound implications for understanding the nature of reality and has led to technological advancements such as semiconductors and quantum computing.