Cryptocurrency is decentralized digital money designed to be used and transmitted over the Internet. It is managed by peer-to-peer networks through distributed ledgers known as blockchains. The first cryptocurrency, Bitcoin, was designed to transfer value via currency (where 1 $BTC = $X), while other cryptocurrencies, like Ethereum and Solana, allow users to go beyond solely transferring value.
Non-fungible tokens (NFTs) are a kind of crypto or digital asset in which each token is unique and may have a different perceived value, in contrast to assets like bitcoin or dollar bills in which each bitcoin and dollar bill has the same value as an interchangeable bitcoin and dollar bill, respectively.
Crypto:
https://www.coinbase.com/learn/crypto-basics/what-is-cryptocurrency
https://www.oswego.edu/cts/basics-about-cryptocurrency
NFTs:
https://chain.link/education/nfts
https://www.coinbase.com/learn/crypto-basics/what-are-nfts
https://www.gemini.com/cryptopedia/nft-non-fungible-token-crypto-collectibles