⛓Intro to Blockchain
Blockchain according to Etherium: A blockchain is a database of transactions that is updated and shared across many computers in a network. Every time a new set of transactions is added, it's called a “block” - hence the name blockchain. Most blockchains are public; you can only add data, not remove it. If someone wanted to alter any of the information or cheat the system, they’d need to do so on the majority of computers on the network.
Blockchain according to Algorand: A blockchain is a public ledger (or file) of transactional data, distributed across multiple computers (“nodes”) in a network. All of these nodes work together, using the same set of software and rules, to verify transactions to add to the finalized ledger. Compare this to a traditional ledger of transactional data that may live in a single database on a few computers that only certain people have access to. The “block” part of “blockchain” refers to a set of transactions that are proposed and verified by the other nodes and eventually added to the ledger. The “chain” part, refers to the fact that each block of transactions also contains proof (a cryptographic hash) of what was in the previous block. This pattern of capturing the previous block’s data in the current block continues back to the start of the network (the genesis block) creating a publicly verifiable and tamperproof record of all transactions, ever.
NFTs according to Etherium: NFTs are tokens that we can use to represent ownership of unique objects. They allow us to tokenize things like art, collectibles, and even real estate. They can only have one official owner at a time and are secured by the Ethereum network; no one can modify the ownership record or copy and paste a new NFT into existence.
NFT stands for "non-fungible token." "Non-fungible" is an economic term that can be used to describe things like your furniture, a song file, or your computer. Tokens are not interchangeable with other items because they have unique properties. Fungible items, on the other hand, can be exchanged because what defines them is their value rather than their unique properties. For example, ETH or dollars are fungible because 1 ETH/1$ can be exchanged for another 1 ETH/1$.
NFTs according to Algorand:
Non-fungible tokens, or NFTs for short, are unique assets represented on the blockchain. Digital art and collectibles are types of NFTs that you may have heard about, but they only scratch the surface of what is possible.
NFTs are created using Algorand Standard Assets (ASAs), which are built into the protocol and created using a special type of transaction. This is distinct from some other blockchains where a smart contract is necessary to represent assets. You just need to specify a few parameters to identify it as an NFT and link to the metadata so that potential owners have the information they need to validate the integrity of the asset. For instance, you need to set the total amount of units you want to create for this asset to 1 and set the number of decimals to 0. This ensures you create precisely one unit of your ASA and can't divide the newly minted asset. However, you can set the number of decimals to any number according to the ARC-0003 NFT standard up to the protocol limit.