The Start Menu is a launching point for programs and applications in Microsoft Windows. It is essentially a list of destinations to help navigate around the machine, All Programs, Documents, Run, Help (or in newer versions, Help and Support). You can also shut down or restart your machine from this menu.
Prior to Windows Vista, the Start Button contained of the word "Start" and the Windows Logo. With Vista's new theme, the word "Start" has been replaced by a blue Windows "pearl" logo.