Theta waves are a type of brainwave that oscillate between 4 to 8 Hz. They are commonly associated with light sleep, relaxation, and deep meditation. During these states, the brain can access creativity, intuition, and emotional processing, making theta waves important for mental well-being and cognitive functions. These waves are often observed in EEG readings when a person is in a relaxed state or just before falling asleep. They play a crucial role in hypnotherapy and neurofeedback practices, where individuals aim to enhance their mental states and improve focus or relaxation through training their brainwave patterns.