Monero is a cryptocurrency that emphasizes privacy more than most other coins. Usually, every transaction on the blockchain is public, and anyone can see who is sending money to who, and the balance of anyone's wallet. Monero keeps this private.
MoneroOcean is a service that lets you mine other coins, and pays you in Monero.
The algorithm used to mine Monero is called RandomX, hence the abbrievation for Monero, XMR (RandomX MoneRo). RandomX is excellent for CPU mining, in fact, you almost definitely will use it for that, but when it comes to GPU mining... it's not at all profitable. This is not really a fault, and it was made specifically like this to not make GPU prices go insane like 2021, and to discourage people from buying dedicated mining devices. It also keeps Monero profitable to mine for normal computers unlike large coins like bitcoin. You can mine a different coin with a different a