A quantum state is a mathematical description of a physical system in quantum mechanics. It encapsulates all the information about a particle, such as its position, momentum, and energy. Quantum states can exist in multiple configurations simultaneously, a phenomenon known as superposition, which is fundamental to the behavior of particles at the quantum level. In quantum mechanics, quantum states are often represented using wave functions or state vectors. These representations help predict the probabilities of finding a particle in various states when measured. The concept of quantum states is essential for understanding phenomena like quantum entanglement and quantum computing.