Tofu or bean curd is a soft white food made by coagulating soy milk, and then pressing the resulting curds into blocks. It is of Chinese origin, and part of East Asian and Southeast Asian cuisine such as Chinese, Japanese, Korean, Indonesian, Vietnamese and others. There are many different varieties of tofu, including fresh tofu and tofu that has been processed in some way. Tofu has very little flavor or smell on its own, so it can be used either in savory or sweet dishes, and is often seasoned or marinated to suit the dish.
Tofu originated in Han dynasty in ancient China, Li Shizhen in Ming Dynasty described the method of making tofu in Bencao Gangmu. Tofu and its production technique were subsequently introduced into Korea, then Japan during the Nara period, and Taiwan. It also spread into other parts of East Asia as well. This spread likely coincided with the spread of Buddhism as it is an important source of proteins in the vegetarian diet of East Asian Buddhism.
Tofu is low in calories, contains a relatively large amount of iron and contains little fat. Depending on the coagulant used in manufacturing, the tofu may also be high in calcium and/or magnesium.
Nice that it's there for vegetarians, but its tendency to absorb everything around it turns it into edible baking powder. What happens is a disgustingly spongy texture with the taste of everything on you plate, whether or not it goes together.