In one line
A piece a creator publishes on their own account, to their own audience.
A Vadodara food creator posts a Reel about a new café on their profile: that is an influencer post. The audience is the creator's, which is why brands pay for it.
A post is not an advert the brand may reuse forever. Running it as a paid ad, or keeping it up for a set time, are separate terms.
Agree: the publishing date, the caption and any paid use.