Web3 is an umbrella term for an online ecosystem that cuts out the big middlemen on the Internet. Platforms on Web3 don't belong to a central gatekeeper, you don't need to browse the internet through a search engine like Google. It uses blockchain, the same system used by cryptocurrencies and NFTs.
$WEB3INU is a blockchain token (like any cryptocurrency) that you can buy, trade, use and spend on WEB3 (the on-chain layer of Web3 games). You can buy them with cryptocurrencies and FIAT within the game and on the secondary market. In addition, NFT generates $WEB3 as revenue from pre-sale to On-Chain layer release and before, as a core game mechanism.