When most people are referring to headaches, it is a tension headache - a headache caused by muscle tightness across the neck and head. It is usually an ache which is consistent, and may go across...
It can last for any amount of time. It generally can last from a hour or two, from the first symptoms a migraine (these can be very different for different people, auras, sounds sensitivity, etc. )...
Migraines are sometimes caused by cold food products. Have you ever had a headache eating slush? In some people this can cause a migraine.
Migraine headaches are induced differently for each person...