What Is Ethereum? Architecture Layers and Developer Overview

Frequently Asked Questions

01.Is Ethereum Proof of Work or Proof of Stake?

Ethereum switched from Proof of Work to Proof of Stake in September 2022 with The Merge. Since then, over 1.04 million validators have secured the network by staking ETH, with approximately 34 million ETH staked as of January 2025, roughly 28% of total circulating supply (Everstake, 2025). Energy consumption dropped over 99% at the transition.

02.What programming language is used for Ethereum smart contracts?

Solidity is the dominant language for Ethereum smart contracts, accounting for the vast majority of deployed contract code. Vyper is a Python-influenced alternative prioritizing auditability and simplicity. Both compile to EVM bytecode. As of 2024, over 6,244 monthly active developers work across the Ethereum ecosystem (Electric Capital, 2024 Developer Report).

03.How long does an Ethereum transaction take to confirm?

Ethereum Layer 1 produces a new block approximately every 12 seconds. Most transactions achieve inclusion within one to two blocks. Full economic finality takes around 15 minutes (two epochs). On Layer 2 rollups, user-facing confirmation is near-instant, though L1 withdrawal windows vary: 7 days for optimistic rollups, minutes for ZK rollups.

04.What is the difference between Ethereum L1 and Layer 2?

Ethereum L1 is the base chain where all final settlement happens. Layer 2s such as Arbitrum, Base, and zkSync execute transactions off-chain, batch them, and post proofs or data back to L1. L2 TVL reached approximately $44 billion in Q1 2025 (L2BEAT), with average transaction costs falling 96% from L1 peaks, from $17.89 to $0.36 per transaction (CoinLedger, 2025).

05.How many validators does Ethereum have?

Ethereum had over 1.04 million active validators as of early 2025, up from approximately 890,000 in late 2024 (beaconcha.in data, Everstake 2025). Each validator stakes exactly 32 ETH. The network requires a two-thirds supermajority of staked ETH to reach finality, making a successful attack prohibitively expensive at current ETH valuations.