Power Armor

Protective suit used in combat, featuring advanced shielding and weapons capabilities as a means of increasing the user's fighting ability. Also known as a powersuit.

Classes

Broadly speaking, there are two categories of power armor: light and heavy. Light armor is an upgrade from regular combat armor that adds mechanical movement assistance, while heavy armor is piloted more like a vehicle a person must get inside and control. In a nutshell, the divide is "worn" versus "piloted".
Common features in all sets are armor plating of various types, anti-projectile plasma barriers, motion assists (thrusters, high jumping), and built-in weapons.
Light suits are more nimble, able to enter building with low structural tolerances and achieve true flight with thrust devices. They use the same types of weapons as regular infantry.
Heavy armor is designed to be tough and durable, with thick shielding and all manner of gadgets built into it. They may have flight capability but are intended primarily for ground use.

Defenses

The primary defense is a plasma sheath as an anti-projectile measure, along with superconducting armor for photoarms fire connected to a heat sink and thermal regulation system which draws out energy dumped in by enemy lasers.

Weapons

Many models of power armor have weapons built in, typically using directed energy as a way to take advantage of the suit's onboard power generation. External weapons can be plugged into suit power as well, many are designed for this. For heavy armor the most common main weapon is a combination gun consisting of a laser and a projectile launcher in one package, looking like a fisheye lens surrounded by barrels. This lets the user take advantage of the capabilities of both types of weapon to attack enemy power units. The laser runs off the suit's generator or built-in coils (or even a miniature nuclear reactor in the heaviest guns), and the projectile launcher is either a rocket rifle or a magnetic accelerator firing ferrous slugs. For melee combat a common feature is a "can opener", a rugged claw-like apparatus designed to grapple an armored adversary and peel their suit open.

Combat

At long ranges, power-armored units can engage with rockets and artillery fire with the most destructive weapons they have. Provided one can put up enough volume to overwhelm the enemy's defenses this is the fastest way to secure kills against armored soldiers. One of the best weapons for this task is are carolinium-tipped rockets. These weapons, if they detonate close enough, are a guaranteed kill even against the toughest modern armor. To defend against long-range attacks, suits are equipped with point-defense lasers and plasma barriers to fragment incoming kinetic projectiles.
However, these long-range surface engagements have been very rare historically because part of the prelude to attacking surface targets with armored troops is gaining space superiority, at which point your ships can blast any enemies who stick their heads out of hardened shelters. Instead the role of armored soldiers has been to clear out such fortified positions when destroying them is not an option.
At medium distances such as urban combat the focus is on ranged attacks to whittle down the enemy's armor. Soldiers will pump each other full of lasers and lead until someone's active systems and armor fail. Because of their durability, power armored troops do not have to worry as much about cover when engaging enemies and can quickly close the distance to finish them off.
Melee combat is quick and lethal. At close distances powerful explosives like c-rockets become unusable because they will do equal damage to both target and firer. Can openers are a prime tool here, whoever is the first to grapple and peel into a crucial spot on the opponent's armor is usually the victor.

Access & Availability

Ubiquitous among military organizations