NFTs (Non-fungible Tokens) are crypto assets which are unique to each other. Digital assets, art and collectibles are it's major components. NFT standard is defined as ERC721 in ethereum network.

No two NFTs are the same unlike 2 coins of the same crypto currency. Example: 2 bitcoins have the same value and inter changeable with each other. But two NFTs (e.g: cryptokitties) are not the same and do not have equal value.

Openzeppelin is a community standard for securing blockchain applications. It provides blueprint for developing decentralized applications as mentioned in the ERC standards. So, we will be importing the required openzeppelin files directly from github.

We will need to import ERC721URIStorage. We will store a JSON content IPFS URL as the tokenURI associated with token IDs. Other ERC721 methods are imported inside the ERC721URIStorage file.

At First, we go to remix IDE which is an online web IDE for ethereum development. Then, we can create a new file inside the contracts folder. The filename extension must be .sol.

We import required the openzeppelin standards in the newly created file

import
"https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC721/ERC721.sol";

import
"https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC721/extensions/ERC721URIStorage.sol";

Then, we write down a simple contract structure extending the ERC721URIStorage

Below is the code to implement a simple NFT minting project.

import
"https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC721/ERC721.sol";

import
"https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC721/extensions/ERC721URIStorage.sol";


contract MyNFTProject is ERC721URIStorage {
    uint private tokenIds = 1;

    constructor(
        string memory _name,
        string memory _symbol
    ) ERC721(_name, _symbol) { }

    function mintToken(string memory tokenURI)
    external
    {
        tokenIds++;
        uint256 newItemId = tokenIds - 1;
        _safeMint(msg.sender, newItemId);
        _setTokenURI(newItemId, tokenURI);
    }
}