"Fungible" means "replaceable by another identical item, interchangeable". Digital assets such as images, gifs, or music files are inherently fungible — making an exact copy is easy. Non-fungible means an item is unique and can’t be replaced. NFTs are a way to make digital assets non-fungible. They introduce ownership of the file which cannot be copied. Generally, NFTs are unique data units with identification information and metadata stored on a blockchain network for security and verification purposes. They can be bought, sold or traded.