NFT marketplaces are online platforms where users can buy, sell, and trade non-fungible tokens (NFTs). These tokens represent ownership of unique digital items, such as art, music, or virtual real estate. Popular marketplaces include OpenSea, Rarible, and Foundation, each offering different features and types of NFTs. Users typically create a digital wallet to store their NFTs and cryptocurrencies, which are used for transactions. The marketplaces often provide tools for creators to mint their own NFTs, allowing artists and developers to showcase and monetize their work in the growing digital economy.