Final answer:
The five basic stages of sleep are characterized by brainwave patterns. Sleep can be divided into two general phases: REM sleep and non-REM (NREM) sleep. REM sleep is characterized by darting movements of the eyes under closed eyelids, and brain waves during REM sleep appear very similar to brain waves during wakefulness.
Step-by-step explanation:
The five basic stages of sleep are further classified into two distinct orders characterized by brainwave patterns. Sleep is composed of several different stages that can be differentiated from one another by the patterns of brain wave activity that occur during each stage. Sleep can be divided into two general phases: REM sleep and non-REM (NREM) sleep. REM sleep is characterized by darting movements of the eyes under closed eyelids, and brain waves during REM sleep appear very similar to brain waves during wakefulness. In contrast, non-REM sleep is subdivided into three stages distinguished from each other and from wakefulness by characteristic patterns of brain waves.