How are Japanese swords different from other swords from around the world?

Compared to Western swords, Japanese swords have longer hilts, are curved on one side of the blade, and the weight of the swords is designed for double-handed ｍanipulation.
Although in samurai films, one may see a scene in which the sword is used with only one hand, in actual fighting the heavy weight of the sword would not allow this.
A unique forging technique is applied in the swordmaking.
A layer of kawagane (skin steel) is welded on top of the shingane (inner steel), steel of a particularly pliant kind.
Since only the blade portion is tempered, it exhibits a temper pattern which, along with the blade's patterned texture resulting from the forging process of the steel, is a distinuishing feature of Japanese swords.