Kanji are Chinese characters adapted for use in the Japanese writing system, consisting of ideograms that represent meanings and can be combined to form new words. They are pronounced in both Chinese (on-yomi) and Japanese (kun-yomi) ways, complicating their study, and a set of 2136 kanji is designated for everyday use. Examples include 日 (sun), 木 (tree), 川 (river), and 山 (mountain), each having specific cultural significance and varying pronunciations.