## 3 Understanding Non-Fungible Tokens
### Importance of NFTs  
It could be argued that the significance of NFTs is that they introduce scarcity in the digital realm, making the ownership and also the trading of digital assets technologically possible. With regards to the former (i.e., ownership) when one buys a NFT, the transaction is registered on the public database of transactions that is the blockchain and as a result no one can question, challenge, obfuscate, or compromise one's ownership of a given asset. Regarding the latter (i.e., trading) NFTs are crypto tokens themselves and, therefore, they can be traded (e.g., bought, sold, transferred, repurchased) on the blockchain, similar to any other type of token. Whereas painters and sculptors could always produce unique physical artifacts, for photographers, when mechanical reproduction was invented \"artists and collectors had to come to terms with the fact that [one could] produce an unlimited number of identical prints of any photograph\" [82]. As a response, in order to achieve authenticity, scarcity and, therefore, collectability, signed editions were introduced [82]. Similarly, as a response to the \"artificial abundance\" [82] of the Internet, NFTs introduce and implement technologically the concept of signed editions in the digital realm [82]. More importantly, they do so in a way that is accepted by common consensus.  
Long before the emergence of NFTs, one could claim and prove ownership of a given asset in a variety of different ways, ranging from image watermarks (in the simplest of forms) to solutions utilising the blockchain, such as Verisart, i.e., a company founded in 2015 before the emergence of NFTs for providing certificates of authenticity to artists, by utilising blockchain technology [83] (Verisart has since adopted NFTs). However, it could be argued that none of these methods were widely known and, as a result, there was no process people could refer to in order to look up the ownership of an asset or its authenticity. Thanks to the relative (i.e., in an anonymised manner) transparency of blockchains, where all transactions are publicly visible by everyone, NFTs make it possible for the first time for anyone with a basic understanding and knowledge of NFTs, to look up the provenance of an NFT, including its creator (i.e., the public blockchain address of the person, or entity, who minted it), the current owner, as well as all previous owners. As an example, given that the vast majority of NFTs are on the Ethereum blockchain, one could track the provenance of an NFT using platforms, such as Etherscan.io, which is a free tool for tracking transactions and looking up the content of smart contracts on the Ethereum network [84]. However, given the ubiquity of anonymity in the decentralised web, it must be noted that rigorous due diligence is required in order to match the creator of the NFT (i.e., the wallet address that minted the NFT) with its real-world counterpart. Towards that direction and in order to minimise fraud, NFT platforms have implemented a verification process for creators to prove their identity. However, not all NFTs are sold through such platforms and therefore it is deemed necessary for collectors to perform their own due diligence.