Blockchain is a shared data ledger that comes in different types- private, public, permissioned, and consortium.
cryptocurrencies
Ripple is a decentralized platform that allows cryptos and fiat currencies to be transferred across international borders, and XRP is its native currency.
Cryptocurrencies have transcended its initial purpose, from digital coins that aim to democratize the payment systems with plenty of uses to meme coins.
Altcoins refer to all other cryptocurrencies other than Bitcoin. In recent years, the definition has expanded to coins other than Bitcoin and Ethereum since many cryptos are forked from one of the two.
Cryptocurrencies like Bitcoin run on blockchains- a shared and immutable list of transactions that allows convenient tracking and recording.