MANET is a mobile ad hoc network. MANET is a self-configuring, infrastructure-less network of mobile devices connected wirelessly. Each device in MANET is free to move independently in any direction and will therefore changes topology to other devices. Ad hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any centralized administration. Routing protocols in ad hoc network are proactive and reactive. In reactive routing also called on-demand routing. Second is proactive which is table driven involves various over heads.