‘Has’ and ‘Have’ are two words that are often used in the English language. They are verbs and precisely referred to as the auxiliary verb. The two actually have relatively the same meaning, such as possess, own, consume, receive, and more. Though they have the same meaning, they can never be used interchangeably.
As earlier stated that they are verbs. Verbs are generally known to be in tenses, i.e., present, past, past participle, and present continuous. Have had all these, but has does not; the major reason is that have the normal verb -a plural verb; while has is a singular verb. Just as other verbs have plural and singular, the same thing is applicable to these two words.
Hence, you can only use have with first and second person singular and plus pronoun or noun, as well as the third person plural noun or pronoun, such as I, we, they, you, etc., while you should use has with third-person singular noun or pronoun, such as he, she, it, etc.