Blockchain technology continues to expand its reach due to its widespread adoption in various industries and fields. Its popularity stems from its numerous economic potentials, both direct and indirect. From cryptocurrency projects to decentralized finance, non-fungible tokens, the Metaverse, and Web3, it remains one of the most highly-rated technological discoveries in recent years.All of these advancements were made possible by the benefits and revolution brought about by blockchain technology, which has been used to solve problems and streamline processes in various industries. One of its rarely discussed use cases, even within its crypto-based communities, comes in the shape of the NFT marketplace. Here, we will take a look at the biggest marketplace of them all, in an extensive guide to industry leader, Opensea.What is a Marketplace?An NFT marketplace is an online platform, either public or private, where non-fungible tokens can be purchased through either auctions or immediate sales. It operates similarly to online retail stores, where available products are displayed for potential buyers to browse. Similarly to traditional online retail stores, NFTs are listed on marketplaces for investors and enthusiasts to choose from a selection of available pieces.A marketplace could be a private platform where participation is restricted to a few whitelisted members. It can also be a public platform open to all and sundry to participate in minting, buying, and selling various NFTs. One of the leading public marketplaces championing the NFTs’ niche is OpenSea.What is OpenSea?OpenSea is an online public marketplace where NFTs are minted, listed, bought, and sold in exchange for cryptocurrencies. It is the premier marketplace and was co-founded by Devin Finzer and Alex Atallah on December 20, 2017. According to DappRadar, OpenSea has recorded over $34B in total trading volume from over 2.5M traders since inception. Its highest daily trading volume of $405.75M was recorded on May 1, 2022, making it the busiest and top marketplace.The platform supports blockchain networks like Ethereum, Polygon, Arbitrum, Optimism, Klaytn, Avalanche, BNB, and Solana. This means NFTs can be minted on OpenSea using either of these networks in the form of Artworks, Photos, Music, Collectibles, Gaming Assets, Metaverse LAND, and more.How to Create An OpenSea AccountBefore creating an account, you need the following:A non-custodial crypto wallet The crypto wallet stores digital tokens (crypto and NFTs) as well as making and receiving payments for buying and selling NFTs. The platform is compatible with Metamask, TrustWallet, WalletConnect, Coinbase, Phantom, Core, and other non-custodial wallets.Discover the best wallet to suit your needs >> HereCryptocurrencies are digital currencies spent on decentralized networks. OpenSea supports ETH, WETH, UNI, USDC, and over 100 other cryptocurrencies as a medium of exchange for buying and selling NFTs and offsetting transaction fees on the platform.So before setting up an account on OpenSea, ensure you have a wallet containing the required cryptocurrency as well as the network token to cover gas fees. Having prepared these necessities, let’s dive into creating your OpenSea account.The first step in creating an account is to go to the OpenSea homepage and click on the “Create” tab at the top right corner.A page will pop up asking you to connect with your wallet. In this case, we linked to our Metamask wallet.After clicking on the wallet, a prompt notification pop-up will ask you to authorize a request. Click on the “Sign” tab, and then you’ll be redirected to the homepage showing your account has been created, as indicated with a bluish ball.Now that you’ve successfully created your OpenSea account, you can mint, list, buy, and sell NFTs on the platform.How to Mint NFTs on OpenSeaMinting NFTs means creating an NFT, which involves uploading your preferred digital file on a blockchain network to be recorded on an immutable distributed ledger technology (DLT).The first step in minting an NFT is clicking on the “Create” tab again after signing in to your account.It will load a page where you are expected to input necessary information like name, description, and others, including the digital file in the required fields.The name of your NFT should be in the “Name” field.The “External link” field is not compulsory, but you can include a URL link that explains your NFT in more detail.The “Description” field is meant for a detailed description of your NFT.The “Collection” is meant for a collection name if you have one.The “Properties” drop-down allows you to input the properties or attributes of your NFT, like its color, size, shape, and other physical features. You can add as many as you have by clicking on the “+ and Add more” tabs, then click on the “Save” tab.6. Underneath the “Blockchain” field, select your preferred blockchain from Ethereum, Arbitrum, Avalanche, Klaytn, Polygon, Optimism, and Solana. In our example, we will use ‘Ethereum’.Next, click on the “Create” tab. You’ll be asked to verify you’re not a robot via a captcha.After verification, a small page will pop up noting you’ve just created your NFT, which you can share on your social media page like Facebook, Twitter, and Telegram.Your NFT has been successfully minted on a blockchain network.How to List and Sell NFTs on OpenSeaListing NFTs means displaying them on the public marketplace for potential buyers (investors and enthusiasts).Before you can list and sell your NFT, you must set a price. To do that, click on the “Sell” tab at the top right corner of the page.Fill in the amount you want to sell your NFT. You can set a fixed price for direct sales or click the “Timed Auction” to open it for bidding. For the sake of this guide, we’ll stick to “Fixed Price.”The “Duration field” allows you to select how long you want your NFT to be listed.After filling out the necessary fields, click on the “Complete listing” tab.Listing NFTs on OpenSea is free; the 2.5% service fee will only be deducted after selling your item. You can also earn up to 10% royalties on each secondary sale of your own, personally created, NFTs.Another notification will pop up on your Metamask wallet; click on the “Sign” tab.Then you’ll receive another notification on your OpenSea page that your NFT has been listed.How to Buy NFTs on OpenSeaPurchasing NFTs on OpenSea is easy, especially if it’s your first time. However, before clicking on that ‘buy’ button, triple check its the official collection, and not some cleverly disguised clone project.As usual, prepare a wallet and send supported crypto tokens to the wallet, then go Opensea homepage.Search for your preferred collection using the “Search” field or navigate through available items to find one that appeals to you.After deciding what to buy, click on it to review its details.Most NFTs are usually listed with a “Timed Auction,” not a “Fixed Price.” This means you will have to make an offer to the seller. Note that the highest bidder usually wins in this auction. Click on the “Make Offer” tab and input the amount you wish to offer for the item. You will have to wait till the auctioning ends; if you’re the highest bidder, you’ll get the NFT deposited to your wallet. But if otherwise, your crypto will be returned to your wallet.However, if the item was listed under “Fixed Price,” it’s open for immediate purchase. In this case, there’ll be a “Buy Now” tab to click, and you can conclude from there.To verify if you’ve gotten the NFT you purchased, go to your account and click on your “Profile” tab. Your newly purchased NFT will be under the “Collected” tab.Now you’re up and running within the NFT ecosystem and have a fair idea of how every NFT marketplace operates. So, jump in and get creating, trading and collecting in this new underexplored frontier of Web3!Want more? Connect with NFT PlazasJoin the Weekly NewsletterJoin our DiscordFollow us on TwitterLike us on FacebookFollow us on Instagram*All investment/financial opinions expressed by NFT Plazas are from the personal research and experience of our site moderators and are intended as educational material only. Individuals are required to fully research any product prior to making any kind of investment.Technical writer, an enthusiast for everything blockchain and decentralized world.