The MOLLE system allows for a lot of configuration and customization. One of those methods is with the use of different pouches that carry different types of equipment. Different types of MOLLE gear pouches attach to the PALS webbing on compatible backpacks and vests. There are several different types of pouches for carrying food, medical kits, tools and ammunition.
In more of a civilian setting, MOLLE vests are great for paintball and airsoft activities, since several MOLLE pouches can be added to carry extra ammo or various pieces of gear.