The shield has a couple purposes, mainly thermal control to maximize fuel efficiency. The secondary purpose is to protect the engine and other assemblies from road hazards.
The Spartan's were primaraly Hoplites, that means they used to shields called Hoploms and large spears, The shields were important because they helped form the formation as each soldier used his...
It was important for protection and to recognise whose side your on by looking at the symbols. It would be hard to fight a battle without knowing who or who wasn't on your side.
The Roman shield , or Scutum , was an important part of the soldier's equipment and an essential part of his protection while in formation fighting against an enemy while in formation : the scutum...