Mail (also maille, often given as chain mail or chain maille, though this is a modern usage) is a type of armour or jewelry that consists of small metal rings linked together in a pattern to form a mesh. Mail armour provided a highly effective defense against the weapons of the era. Tests conducted by the Royal Amoury at Leeds concluded that, "it is almost impossible to penetrate using any conventional medieval weapon." This construction can ward off a slashing blow by an edged weapon, preventing it from cutting through to the skin. The flexibility of mail meant that a particularly strong blow would often transfer to the user, often causing fractures or serious bruising. It is to be considered however, that most Medieval physicians or physicians of earlier time periods could usually set broken bones, but when it came to preventing infection they were woefully inadequate. Thus the mail was weak in defending against wounds which could be more easily mended but strong against those to which the soldier was most vulnerable. The word chainmail is of relatively recent coinage, having been in use only since the 1700s, prior to this it was referred to simply as mail .
The word itself refers to the armour material, not the garment made from it. A shirt made from mail is a hauberk, if knee-length; haubergeon if mid-thigh length, and byrnie if waist-length. Mail leggings are called chausses, mail hoods coif and mail mittens mitons. A mail collar hanging from a helmet is camail or aventail. A mail collar worn strapped around the neck was called a pixane or standard. It should be understood that this is not like a modern collar that wraps around the throat and back of neck but is rather a very small poncho in that it drapes over the shoulders and covers the breast and upper back.