Darth Vader's armor was a mobile life support system that Darth Vader was forced to wear to compensate for the serious injuries he suffered after his duel with Obi-Wan Kenobi on Mustafar. It was designed to maintain and protect him. His suit followed an ancient Sith tradition, in which the warriors of the dark side of the Force would adorn themselves in heavy armor. The suit was constructed using various methods of Sith alchemy which served to augment Vader's severely diminished physical strength and vitality.
The suit provided a wide variety of life-support systems, the most important among them a complex breathing apparatus, and gave Vader relatively free movement. It was damaged or broken several times during its use, necessitating upgrades and repairs. The suit was finally irreparably broken by Emperor Palpatine's powerful Force lightning aboard the second Death Star after Vader saved his son, Luke Skywalker, from near death.
The armor encased Vader completely, leaving no burned skin exposed. Vader slowly learned to live in this kind of isolation and anonymity, finding ways to cope with his situation, though the suit was not made with the peak technology of its day and was uncomfortable to wear. As a way of overcoming its limitations, Vader was forced to change his lightsaber style. Additionally, to escape the armor's claustrophobic nature, Vader had several meditation chambers built, in which he could remove his mask and suit and still survive. However, Vader longed to be less dependent on his armor, and tried at times to function without it, but he labored in vain.