In simple terms, DHCP determines if your IP is static or dynamic and the length of time an IP address is assigned. Dynamic Host Configuration Protocol is controlled by a DHCP server. Your router can be a DHCP server...and if you're on a home network, it most likely serves this purpose.
Researchers report that the average adolescent needs eight and a half to nine and a half hours of sleep each night. But in a poll taken in 2006 by the National Sleep Foundation, less than 20 percent reported getting that much rest on school nights.
Each person is different depending on their age but in general, healthy adults need around 7 hours of sleep per night, with children and older people needing more. Teens typically need nine or more hour per evening, with younger children needing ten to fifteen hours for restoration.