Dreams occur during sleep and involve sequences of images, sounds, and feelings. The sleep cycle consists of four stages over 90-120 minutes including stage 1 of light sleep, stage 2 of deep sleep, stage 3 of very deep sleep, and stage 4 of REM or rapid eye movement sleep. Dreams are important as they can help people overcome irritability, anxiety, depression, moodiness, lack of concentration, and memory loss. There are different types of dreams like daydreams, lucid dreams, nightmares, recurring dreams, healing dreams, prophetic dreams, and signal dreams.