What exactly are these “play-to-earn” games?

Answer 1

To put it another way, play-to-earn games are Video Games in which the player has the opportunity to win rewards that have value in the real world. People have made money from playing video games for several years thanks to farming activities and unauthorised marketplaces for in-game stuff. However, the introduction of blockchain technology and NFTs have changed the game’s rules. Non-fungible tokens, also known as NFTs, are tokens that are cryptographically distinct from one another and can be used to demonstrate ownership of digital material such as photographs or songs. Players can acquire ownership of in-game objects, such as virtual apparel or plots of land, in games powered by blockchain technology.