用途 (yòng tú) is a noun meaning 'use, application' — it refers to the purpose or function something can serve. It is similar to 用处 (yòng chù), but 用途 is more common in formal or technical contexts (e.g., product descriptions), while 用处 is more everyday and emphasizes practical benefit. 用法 (yòng fǎ) means 'way of using' (instructions), not purpose.