usually steel, but sometimes armor
Metal armor (plate armor) was not invented in medieval age, it was already used by ancient greeks and romans. Metal armor allowed knights to be stronger.
Metal.
metal, leather and hides
iron
People rode horses long before there was metal armor.
Chain mail
Yes
Both samurais and knights used swords as their primary weapon, such as the katana for samurais and the longsword for knights. They also both used armor for protection in battle, with samurais wearing elaborate armor made of lacquered plates and knights wearing suits of armor made of metal. Additionally, both warriors used bows and arrows in combat.
knights wore metal armor which was very hard to carry on because it weighed many pounds!
Knights wear armor as primary protection for their bodies. It was also an indication of their status as part of a military and social elite.
Knights' mail was made out of iron rings. When the knights progreesed to plate armor, it was made of still plates sewn together. The Steel got better in quality over the ages, especially when firearms came to Europe.
They would wear suits of metal plate armor, but early knights wore tough leather