Dreams are essentially stories we play out in our head overnight; they can follow a linear narrative or be abstract. Scientists estimate that we have roughly 3-6 dreams in one night and around 95% of these dreams are forgotten the following morning.
Dreaming occurs during the REM (Rapid Eye Movement) cycle of sleep. During REM sleep, your eyes move quickly in different directions. Usually, REM sleep happens 90 minutes after you fall asleep. You tend to have intense dreams during this time as your brain is more active.