Facebook Posts are public messages posted to a Facebook user's entire audience or on a specific person's profile page (or "wall"). Businesses utilize posts to continually provide a presence to their audience and potentially attract new followers.
Ads that run exclusively through Facebook's advertising platform. They can appear in Facebook's feed, Messenger, and even on non-Facebook apps and websites. They come in a variety of formats such as single image, video, slideshows, and more, and can be targeted to extremely specific audiences.