Zanpakuto
A Zanpakuto is a type of sword used in the world of Bleach. This weapon is used by shinigami.
(And for all thoses bleach fans, yes I know it's also used by other groups, but thoses groups won't be mentioned until later)
A zanpakuto is part of the owner's soul. Owner's of the Zanpakuto need to know it's name if they want the Zanpakuto to perform releases and become stronger. When an owner doesn't know the name of their Zanpakuto, their zanpakuto is called an: Asauchi. Their name, can give a clue to what the zanpakuto's power will be. A Zanpakuto's ablities is not the same as another Zanpakuto's, the reason why is that a Zanpakuto's abilities match their owner's characteritics and personality. However, even though they do have ablities to match their owner's characteritcs and personality, they are not a mirror of their owner, they can be independent, which is why they are also recongized as not only a weapon, but a partner in battle. Not every single Shinigami knows the name of their Zanpakuto due to that they can not get greater power. Since these weapons are part of the owner's soul, once they are broken they can not be replaced, but they can make themselves unbroken, but at a slow rate. These weapons being part of the owner's soul, are also easy for the owner to use. As shinigami get greater powers, their zanpakuto can change form by allowing the inner bineg to manifest itself to a greater degree in the outside world. The sword and the inner being are synonymous to each other. (Italic is from:http://bleach.wikia.com/wiki/zanpaku%C5%8D#Shikai)
The apperances of most Zanpakuto's look like katana's, with slight diffrences like the hilt (part of the sword above the grip). The expections of this are Urahara's (he's the log out icon! he's also known as Mr. Hat and clogs) and Captin Yamamoto. Every single Zanpakuto is diffrent, but for Shinigami, there are a few things that they have that is the same. A Zanpakuto can purify hollows, send souls to the afterlife (afterlife is soul society or the Hell gate Note:Not so sure if that's the name of the gate)