Regarding the armor:
https://www.esquire.com/entertainment/movies/a29773587/beskar-the-mandalorian-armor-explained/And Episode One of the new Disney+ series promises we'll explore this lush background beginning with the Mandalorian's legendary armor made from Beskar Iron. This substance is described as "an alloy used in Mandalorian armor, notable for its high tolerance to extreme forms of damage. The metal was durable enough to withstand a direct blaster shot, and could potentially withstand the slash or glancing blow of a lightsaber, though could be penetrated with a direct stab."
This armor is worn by the warrior race from the planet Mandalore. So far, because of the Mandalorian's bloody history, we've only seen a few examples of these people in the Star Wars films, including Boba Fett and Jango Fett. As the Star Wars wkiki describes them:
Mandalorians were a predominantly human ethnolinguistic cultural group who originated on the planet Mandalore. Mandalorians had a particularly unique role in galactic history as legendary warriors against the Jedi, and could be commonly found not only on the Mandalorian homeworld and its moon, Concordia, but across Mandalorian Space and the galaxy at large on worlds such as Kalevala, Krownest, and Concord Dawn. Mandalore had a largely martial history, but by the time of the Clone Wars the pacifist and reformist New Mandalorian political faction controlled Mandalore's government, led by Duchess Satine Kryze. This led to internal conflict with other Mandalorian groups like Death Watch, who wanted to maintain the warrior ways of their Mandalorian heritage.
Mandalorian's are best known by the armor with T-shaped helmets made famous by Boba Fett in George Lucas's original trilogy. And this armor appears to be a key plot point in this new series, which takes place shortly after the events of Return of the Jedi and before The Force Awakens. In The Mandalorian's first episode, our mysterious protagonist is granted a slab of Beskar from Werner Herzog's character in exchange for taking a bounty. He brings it to what appears to be some sort of Mandalorian tribal hut, where a fellow Mando flattens it into a "pauldron," and attaches it to the bounty hunter's armor.
The blacksmith mentions that the metal was recovered during the Great Purge. Now, it's unclear as to what the Great Purge is referencing. This might have something to do with The Empire's occupation of Mandalore. Or it could possibly have something to do with Order 66, the massacre of the Jedi carried out by The Empire. What we do know is that this Beskar armor will have a sacred place in this story going forward, as our character delves more into the Mandalorians' storied past.
