What are EVM and ABI?

EVM - A series of instructions called opcodes. These opcodes define very simple operations like adding two numbers. Loading data from memory.

There are more than 100 opcodes defined in the Ethereum yellow paper.

coding directly with opcodes will be very tedious so we need higher languages like solidity to help us reason at a higher level of abstraction.

When you deploy a smart contract the creation code is executed and the runtime code is stored in the Ethereum network.

ABI - ABI is the interface of the smart contract, Which means the set of functions that can be called from outside of the smart contract.

The ABI is used outside of smart contracts by Ethereum client libraries like web3.

The ABI only defines the function signatures. That means the function names, the argument types, and in written times. But it does not define the implementation of the function. The ABI also defines the events of the contract.

in this function, foo and bar will be part of the ABI. baz is internal so it’ll only be called from the inside the smart contract.