In some instances, such as Izanagi-no-Mikoto and Izanami-no-Mikoto, kami are personified deities, similar to the gods of ancient Greece or Rome. In other cases, such as those concerning the phenomenon of natural emanation, kami are the spirits dwelling in trees, or forces of nature.
Kami may, at its root, simply mean "spirit", or an aspect of spirituality. It is written with the kanji "神", Sino-Japanese reading shin or jin; in Chinese, the character is used to refer to various nature spirits of traditional Chinese religion, but not to the Taoist deities or the Supreme Being. An apparently cognate form, perhaps a loanword, occurs in the Ainu language as kamuy and refers to an animistic concept very similar to Japanese kami. Following the discovery of the Jōdai Tokushu Kanazukai it is now known that the medieval word kami (上) meaning "above" is a false cognate with the modern kami (神), and the etymology of "heavenly beings" is therefore incorrect. Shinto kami are located within the world and not above it. In fact, traditionally human beings like the Emperor could be kami. No need was felt to locate them beyond this world. In his Kojiki-den, Motoori Norinaga gave a definition of kami:" any thing or phenomenon that produces the emotions of fear and awe, with no distinction between good and evil."
Because Japanese does not normally distinguish singular and plural in nouns, it is sometimes unclear whether kami refers to a single or multiple entities. When a singular concept is needed, "-kami" (神?) or "-kamisama" (神様?) is used as a suffix. It is often said that there are ya-o-yorozu no kami (八百万の神?, countless kami) in Japan. ("八百万" literally means eight million, but idiomatically it expresses "uncountably many" and "all around"—like many East Asian cultures, the Japanese often use the number 8, representing the cardinal and ordinal directions, to symbolize ubiquity.)
Similarly, gender is also not implied in the word kami, which can be used to refer to either male or female kami. The word "megami" (女神?), the use of female kami is a fairly new tradition.