ERC 20 v ERC 721

ERC20 and ERC721 are two popular standards for representing tokens on the Ethereum blockchain. While they both serve similar purposes, they have some key differences that make them suitable for different use cases.

ERC20 is a standard for representing fungible tokens, which means that all tokens of a particular type are interchangeable and have the same value. This is similar to how physical currency works – for example, all U.S. dollars are interchangeable and have the same value, regardless of who owned them previously.

ERC20 tokens are widely used for a variety of purposes, including representing cryptocurrency, enabling fundraising through initial coin offerings (ICOs), and even implementing loyalty programs. Because ERC20 tokens are interchangeable, they can be easily exchanged for other tokens or cryptocurrency on exchanges, making them highly liquid.

On the other hand, ERC721 tokens represent non-fungible assets, which means that each token is unique and cannot be replaced by another token. This makes ERC721 tokens particularly well-suited for representing one-of-a-kind items such as collectibles, digital art, and virtual real estate.

One of the main differences between ERC20 and ERC721 is the way they are stored on the blockchain. ERC20 tokens are stored in a single, shared account, while ERC721 tokens are each stored in a separate account. This makes it easier to track the ownership and transfer of unique assets using ERC721 tokens.

What are minimum required functions of ERC20 smart contract ?

The ERC20 standard defines a set of functions that must be implemented by any smart contract that wants to issue ERC20 tokens. These functions are necessary to ensure that ERC20 tokens are interoperable and can be easily integrated into other systems, such as exchanges and wallet applications.

Here is a list of the minimum required functions for an ERC20 smart contract:

1. totalSupply(): Returns the total number of tokens in circulation.
2. balanceOf(address _owner): Returns the balance of the specified address.
3. transfer(address _to, uint256 _value): Transfers a specified number of tokens from the contract owner’s balance to the balance of another address.
4. transferFrom(address _from, address _to, uint256 _value): Transfers a specified number of tokens from the balance of one address to the balance of another address. This function is often used in conjunction with an “allowance” system, where one address allows another address to transfer a certain number of tokens on its behalf.
5. approve(address _spender, uint256 _value): Approves another address to transfer a specified number of tokens on the contract owner’s behalf. This function is often used in conjunction with transferFrom().
6. allowance(address _owner, address _spender): Returns the number of tokens that a specified address is allowed to transfer on behalf of the contract owner.

In addition to these minimum required functions, ERC20 contracts may also implement additional functions and features, such as the ability to burn tokens (permanently remove them from circulation) or pause and resume token transfers.

It’s worth noting that while these functions are required to be present in an ERC20 contract, they may not necessarily behave as expected in all implementations. It’s always a good idea to carefully review the code and documentation of any ERC20 contract before interacting with it.

What are the minimum required functions of the ERC 721 contract?

The ERC721 standard defines a set of functions that must be implemented by any smart contract that wants to issue ERC721 tokens. These functions are necessary to ensure that ERC721 tokens are interoperable and can be easily integrated into other systems, such as exchanges and wallet applications.

Here is a list of the minimum required functions for an ERC721 smart contract:

1. totalSupply(): Returns the total number of tokens in circulation.
2. balanceOf(address _owner): Returns the number of tokens owned by the specified address.
3. ownerOf(uint256 _tokenId): Returns the address that owns a particular token.
4. transferFrom(address _from, address _to, uint256 _tokenId): Transfers ownership of a particular token from one address to another.
5. approve(address _to, uint256 _tokenId): Approves another address to transfer a particular token on the contract owner’s behalf.
6. getApproved(uint256 _tokenId): Returns the address that is approved to transfer a particular token on behalf of the owner.

In addition to these minimum required functions, ERC721 contracts may also implement additional functions and features, such as the ability to set and retrieve metadata for each token, or to implement an “allowance” system similar to the one used in ERC20 contracts.

It’s worth noting that while these functions are required to be present in an ERC721 contract, they may not necessarily behave as expected in all implementations. It’s always a good idea to carefully review the code and documentation of any ERC721 contract before interacting with it.