The word "卡通" is formed through a process of phonetic borrowing from English. It is a direct transliteration of the word "cartoon", where the two Chinese characters "卡" (kǎ) and "通" (tōng) were selected specifically because their combined pronunciation closely approximates the sound of the English source word. The formation is thus purely sound-based, with the original meanings of the individual characters (which are unrelated to animated images) being largely irrelevant for this purpose.