What kind of word is do does?

Excuse me, could you please clarify what you mean by "What kind of word is 'do' or 'does'?" Are you asking about the grammatical function of these words in English, or perhaps their classification in terms of parts of speech? If it's the former, 'do' and 'does' are often used as auxiliary verbs, helping to form questions, negations, and emphasis. If it's the latter, both 'do' and 'does' belong to the verb category, specifically, they are modal verbs or helping verbs. Could you please elaborate on your question so I can provide a more accurate answer?