Getting better sleep does not mean spending longer in bed but obtaining a higher quality of repose. Usually, this will mean being asleep for a set number of hours in each 24-hour period, but the degree to which people need sleep varies from individual to individual. Therefore, obtaining better sleep is about quality rather than quantity for most people. In sleep, there are two known phases, REM sleep and non-REM sleep. To get better quality rest, you need both periods to occur. Non-REM sleep is when the brain lowers its activity, and your heart rate will drop. This is what most people call deep sleep. REM sleep is so-called for the rapid eye movements that go with it. Brain activity picks up at this point, and we tend to dream at such times. Although not yet fully understood, dreaming appears to help us process our waking lives at a subconscious level. Without both types of sleep, we don't get the quality we need to function normally in the day time.