Like all Sith armor or suits Vader's was meant to be protective and intimidating although the armor and mechanics were actually quite outdated. The tech that was used was even more outdated than Grievous's armor.

We will start with the helmet. 

Darth Vader's helmet was made out of Durasteel, Obsidian, and Plasteel. It was carved to fit Anakin's head and too look like a Skull to enhance the fear factor. It is rumored the suit had a very strong hull that had been strengthened via Sith dark alchemy.  The suit had two jagged ridges that went over Vader's eyes to "accent" them. The helmet locked into the mask with a pressurized seal very similar to a Class C spacesuit. The suit had thousands of needles poking into Vader's skin and nervous system all at once to analyze brain waves and to help neutralize his nervous system.His helmet would help to circulate air and filter it then it would be sucked down into his lungs. The mask went halfway around Vader's head in a circular fashion. The mask came in two parts. The regular mask which covered his face and then a two sided slanted mask which would also help deflect potential energy onto the thick shoulder pads. The slanted part of the mask was actually made to resemble a Japanese samurai Kabuto. 

Cleary George took great inspiration from the Japanese Samurai. That's what the Jedi were based on in the first place. 

Now onto the torso.

Vader's pectoral armor was mainly one giant piece of grey hinted Durasteel. It weighed 26 pounds, It was both resistant towards Blaster bolts and Energy Sword strikes. When it is hit by either it would still scuff up the armor but at least it would provide protection. A big issue is the weight of the armor made it difficult for Vader to raise his arms above his shoulder but Vader adapted and overcame that difficulty. Around his abominable area he wore a plastoid griddle  to protect his synthetic and organic organs. On his back hidden by his cape he would also wear a backpack. His cape also was made up of armor which would help to aid his back protection even further. So the worst place to strike would be Vader's back. Over his solar-plexus he had a life support regulator which he could control. This regulator also enabled his sound when he breathed. Vader could turn this sound off like he did in the comics and in Rogue One. He could also control his built in bathroom system with this chest regulator and he could control his cardiopulmonary and neural systems. So Vader's most vulnerable spot to strike would be his chest regulator but it's right in the middle of his chest so it would be risky to strike there.

  Vader wore a black ribbed, padded, multi-ply body glove that covered everything below his neck. The quilted suit was blast-dampening, and was made of a fireproof material that provided some protection against flames and corrosive gasses.

Now onto Gauntlets and Boots.

Vader's gauntlets had a variety of Mandalorian designs in it.  he right glove being a Mandalorian crushgaunt fitted around. The gauntlets word weaved out of tiny Mandalorian steel.

Vader's black all terrain boots were mostly made out of Durasteel. They offered shin protection which was the heaviest piece of Armor Vader had. His boots have a magnetic field which could be controlled by voice commands. If Vader was fighting on top of a ship he could activate the magnetic fields and he would sort of be like Spiderman he would be able to attach to any magnetic material.

I think it's safe to say not to mess with Darth Vader.

Thank you for reading! May the Force be with you, always.