There are three different types of armour. All of these armours benefit you in different ways.
ArmoShell: ArmoShell utilizes a strong heavyweight metal compound found currently only in a single African digging site.
These types of armour mainly improves your endurance, which decreases how much damage you take. It also makes you look like a human bulldozer!
ExoGear: Based on experimental U.S army technology, the ExoGear provides greater strength with compromised armor effectiveness.
These types of armour mainly improve your strength, which results in greater MELEE damage.
ProtoSuit: A prototype suit, developed by a Japanese government facility, which converts muscle strength into superior movement speed.
This type of armour mainly increases your agility, which determines how fast you can run.
These are placed on three different parts of the body; arms, torso and legs. They also look cool. There are 5 levels of each.