Where Bitcoin was hailed as the digital answer to currency, NFTs are now being touted as the digital answer to collectables, but plenty of sceptics fear they're a bubble waiting to burst.What is a non-fungible token?In economics, a fungible asset is something with units that can be readily interchanged - like money. With money, you can swap a £10 note for two £5 notes and it will have the same value. However, if something is non-fungible, this is impossible - it means it has unique prope...