When Bruce Wayne was in his study in Wayne Manor he was wondering what would be an effective way to fight criminals. And just then, like an omen, a bat flies through the window. He then realized that a bat is a terrifying creature, and that if he dressed up like a bat, he could strike terror into criminal hearts. During his studies, he learned that criminals were, for the most part, a superstitious, cowardly lot. So he knew he could use that to his advantage.
Stylistically, the Batsuit was designed to invoke fear in his opponents, particularly the cowl has a frightening appearance to invoke intimidation. But every aspect of the suit's design serves a critical function in Batman's career. The costume is made of kevlar fabric, coated with titanium, making his costume virtually bulletproof, the boots, gloves and spine protect him from falls and lessen the impact. The gloves also contain a bracer that has sharp "scalloped fins," which Batman can use to block an opponent's attack with a sword or knife. His cape contains a thin lattice of flexible rods that can be used to help him glide through the sky. This helps him especially in aerial combat against foes such as Man-Bat. His Utility Belt contains a wide variety of gadgets that come in handy when taking out bad guys, such as Batarangs and other weapons.