What is EVM (Ethereum Virtual Machine)?

Summary

In this informative video, Sahil from QuickNote introduces the Ethereum Virtual Machine (EVM), a distributed state machine that executes smart contracts and processes transactions on the Ethereum blockchain. He explains how EVM, being Turing complete, can handle complex operations and is not limited to Ethereum but is also utilized by other blockchain ecosystems like Polygon and Binance Smart Chain. The video covers the compilation of smart contracts into bytecode, the concept of gas for opcode execution, and the Merkel Patricia tree structure that maintains the state of the blockchain.

Takeaways

• 🖥️ A virtual machine is a simulated computer that can run various operating systems and applications.
• 🔢 Programming languages like Python, JavaScript, and Go need to be compiled into machine code for execution by computers or virtual machines.
• 🌐 EVM, or Ethereum Virtual Machine, is a virtual machine maintained by all node runners in a blockchain network, not just a single computer.
• 💼 Ethereum is more complex than Bitcoin as it is a distributed state machine that processes financial transactions and smart contracts.
• 📝 Smart contracts are written in Solidity for EVM-based environments, but EVM cannot understand Solidity code directly and requires compilation into bytecode.
• 🛠️ Each function in the smart contract's bytecode has opcodes that are machine instructions telling the EVM which operation to perform.
• 💰 Executing opcodes on EVM requires a fee, as it uses resources provided by node runners, and these fees are measured in a unit called gas.
• 🌟 The complexity of smart contract functions determines the amount of gas required, with more complex functions consuming more gas.
• 🌳 EVM is structured as a huge Merkle Patricia tree where accounts are linked with hashes and reducible to a root hash stored on the blockchain.
• 🔄 Once a transaction is confirmed, the Merkle Patricia tree is updated, reflecting the updated state of the blockchain.
• 🔄 EVM is a Turing complete machine, capable of producing an output given enough input, memory, and gas fee, allowing for the conversion of code from other languages to Solidity.
• 🔗 The capabilities of EVM extend beyond Ethereum, as other blockchain ecosystems like Polygon, Avalanche, and Binance Smart Chain also use it as their state machine.

Q & A

What is a virtual machine?

A virtual machine is a software-based simulation of a computer that runs on remote servers, capable of running various operating systems and applications.

Why is a compiler required to run applications on a virtual machine?

A compiler is needed to convert high-level programming languages into machine-understandable language, consisting of zeros and ones, for execution on virtual machines.

What does EVM stand for?

EVM stands for Ethereum Virtual Machine, which is a virtual machine for the Ethereum blockchain network.

How does the Ethereum Virtual Machine differ from a traditional virtual machine?

Unlike traditional virtual machines that run on a single computer, the EVM is maintained by all node runners of the blockchain network and processes not only financial transactions but also smart contracts.

What is a smart contract and how is it related to the EVM?

A smart contract is a program that runs on the blockchain and executes automatically when certain conditions are met. The EVM is responsible for executing these smart contract transactions.

In which programming language are smart contracts typically written for the EVM?

Smart contracts are typically written in Solidity for an EVM-based environment or ecosystem.

Why can't the EVM understand Solidity code directly?

The EVM cannot understand Solidity code directly because it is a high-level language; it must be compiled into bytecode, which consists of opcodes that the EVM can execute.

What is the purpose of 'gas' in the context of the EVM?

Gas is a unit of measurement that represents the computational effort required to execute an operation on the EVM. It is paid as a fee for using the resources of the globally distributed computer that is the EVM.

What is the significance of the Merkel Patricia tree in the EVM?

The Merkel Patricia tree is a data structure used by the EVM to store and update the state of the blockchain, where each account is linked with hashes and reducible to a root hash stored on the blockchain.

What does it mean for the EVM to be a 'Turing complete' machine?

A Turing complete machine, like the EVM, can perform any computation given enough input, memory, and computational steps (gas fee), meaning it can execute a wide range of algorithms and processes.

Why can the EVM execute code written in other programming languages like Python or JavaScript?

The EVM can execute code written in other languages because the underlying logic of the code remains the same; it just needs to be converted into Solidity, which the EVM can understand and execute.

Besides Ethereum, which other blockchain ecosystems use the EVM?

Other blockchain ecosystems like Polygon, Avalanche, and Binance Smart Chain (now called PNB Chain or PNB Smart Chain) also use the EVM as their state machines.