it is very interesting to know the metadata and tag.
for me, i think the tag, is mostly like category of items.
a famous song “price tag” by Jessie J. it talks that everyone can use money to buy happiness, and needs to forget price tag on items.
for some reasons, i do not want to discuss what the song stands for, since it is just a song for entertainment. after learning metadata and tag, i see more knowledge about this song. people give the price tag to mark the level of item. it seems like people use price tag to category different items, higher price for good quality and luxury brand, lower price for normal or cheap quality. price tag is interesting, because it gives category value. people use price tag to search items.