As explained in What are NFTs and what are they for?, NFTs are unique tokens. Meanwhile, digital collectibles that are semi-fungible can also be created on the blockchain.
For example, in the SPOZZ ecosystem, a musician can create and sell 10,000 copies of a song of his authorship. These copies can be collected by his fans and they will be able to verify the legitimacy of the copies (see How to verify the authenticity of the NFTs we have created in the SPOZZ Marketplace?).
If you go to your MetaMask, for example, and open the Polygonscan, Etherescan or BSCscan section (depending on the network you are on), you will see that there you can differentiate between ERC-721 tokens and ERC-1155 tokens, which is the technical name to differentiate between NFTs and semi-fungible tokens.
To open BSCscan in MetaMask, you should proceed as indicated in the following image (if you were on the Ethereum or Polygon network, you should do exactly the same procedure):
Once you open that section, when you go down the page, you can see that there are different sections, in one of which there are the ERC-721 tokens, which are NFTs, that is, unique tokens. And, on the other hand, there are the ERC-1155 tokens, which are semi-fungible tokens that also exist in the blockchain, so you can corroborate their legitimacy, which collection they belong to and when they were created.
In the following image, in the ERC-721 flap, you can see the NFTs found in that wallet:
In the following image, you see ERC-1155 items, some of which were made by visual artists.
It is worth saying that an ERC-1155 item can not only be made by a musician or plastic artist. A company or project could also launch an ERC-1155 that grants, for example, a discount to all its customers. Therefore, these items, besides having a collectible value, can also have other utilities, which can give them an extra value in the market.
The opportunities are limitless and what can be created and done within the blockchain ecosystem, NFTs and collectible digital items depends on the creativity of each intervening party.