For most people big biceps is the ultimate goal when it comes to training. The dumbbell curl is very important when training for bigger arms. When performing the bicep curl you want to get a a weight that you can move under control. During the Concentric phase of the lift you want the palms up and squeeze the bicep at the top of the lift. Where you will get most of your growth in the bicep is on the eccentric phase of the lift. During the eccentric phase you want to control the weight all the through full range of motion.
The biceps serve as stabilizers for heavy compound lifts as well. Therefore, the stronger and bigger the bicep will give you a stronger squat, press and pull. Having endurance in the bicep will help you in everyday activities such as carrying groceries or holding a baby. These are just some benefits of having a big and strong bicep and big biceps just look cool!