Web3 games are built on the blockchain using web3 libraries/providers, smart contracts and digital wallets.
As in the title this is all about gaming but the difference here is that this decentralized approach uses blockchain technology for the underlying economy of the game.
Assets within the game, possibly weapons or apparel, will be NFT's giving players control and ownership. It's also possible that assets can be transferred to other platforms, something that's not always possible in conventional gaming. You truly own the assets you purchase.
There are two gaming types play-to-earn and walk-to-earn.
Play-to-earn is where the more you play, the more you'll be rewarded with digital assets. Axie Infinity is an example of this where users can buy and breed Pokémon type characters. You win Smooth Love Potions (SLP) which can be exchanged for real money.
Walk-to-earn is where the more you move, the more you earn. Walken is an application where users are rewarded with WLKN (an in app token) for taking part in sporting activities. You can use your tokens on the marketplace to buy fun items to boost your 'CAThlete' avatar.
Before moving on check you fully understand the core concepts of Web3 Gaming.