Can we add changes to the smart contract once it has been deployed?

Question

I am a newbie and am learning about the blockchain and smart contracts.

So my question is can we add changes(features) to the smart contract code once it has been deployed?

and is it possible to create an ERC 20 token that is based on proof of stake? Thanks

Answer 1

No, the very foundation of a blockchain is its immutability, meaning that once a set of data is sent to the blockchain, it can never be modified or changed in any way. Therefore, once you push a smart contract to the Ethereum blockchain, it cannot be changed or manipulated in any way.

It's not entirely possible due to the fact that an ERC20 token is embedded into Ethereum's blockchain. So, when miners are mining the Ethereum blockchain, they're essentially mining every ERC20 token as well.