ERC-20 vs. ERC-721 vs. ERC-1155:-

ERC-20:

The most common token standard on Ethereum
Used for fungible tokens, meaning each token is identical and interchangeable (like currencies)
Defines basic functions like transfer(), balanceOf(), totalSupply()
Examples: Most cryptocurrency tokens like USDT, LINK, or UNI use this standard

ERC-721:

The standard for non-fungible tokens (NFTs)
Each token has unique properties and is not interchangeable
Includes functions like ownerOf() to track who owns each unique token
Used for digital art, collectibles, and unique digital assets
Example: CryptoPunks and Bored Ape Yacht Club NFTs

ERC-1155:

A “multi-token” standard that combines features of both ERC-20 and ERC-721
Can handle both fungible and non-fungible tokens in a single smart contract
More gas-efficient for transfers of multiple token types
Popular in gaming where users might need both fungible items (like in-game currency) and non-fungible items (like unique characters or weapons)
Examples: Many blockchain games and metaverse projects use this standard

The main difference between these standards lies in how they handle token uniqueness and transferability. ERC-20 is for identical, interchangeable tokens, ERC-721 is for unique tokens, and ERC-1155 can handle both types efficiently.