Answer of NFC tags are formatted based on the use case:
But wait there is more – The tag data can be formatted in such a way that the reading device knows what do with it. As an example, if the tag data is a website link, the reader device will know to open up a browser window and connect to the website. If the tag data is a link to a video, it may open up a YouTube application to play the video. NFC can play apart in consumer interaction with advertisements, event kiosks, ticketing system, and other non-industrial applications.
NFC tags are formatted to reflect the use case. This formatting determines whether the NFC tag will act like a tag and issue data on request, be used in payment transactions using secure links, or in a two way mode as part of a phone.