The Ethereum Story · Module 6 · 2022 to 2026 · 35 min
On 15 September 2022 Ethereum changed how it agrees on blocks, from proof of work to proof of stake, and a series of upgrades since then has made everyday use much cheaper.
What you will learn
Explain the difference between proof of work and proof of stake.
Describe what layer 2 networks are and why they lower fees.
Place the main upgrades from 2022 to 2025 in order.
The lessons
Lesson 1: The Merge
On 15 September 2022 Ethereum switched from proof of work to proof of stake in an upgrade known as the Merge. The old chain and the Beacon Chain were joined, and from then on blocks were agreed by stakers, not miners.
The main effect was on energy use. Proof of stake needs far less electricity because it does not rely on competing computers, and the drop was very large.
It did not make fees cheaper or the network faster on its own, a common misunderstanding. Those improvements needed other changes, which came in the following years.
Remember: The Merge changed how Ethereum is secured. It did not change what it costs to use.
Lesson 2: Withdrawals and cheaper layers
In April 2023 the Shapella upgrade let stakers withdraw their ether for the first time. Until then, ether that had been staked was locked in.
The big step for fees was a different idea: layer 2 networks. A layer 2 is a separate network built on top of Ethereum that handles many transactions quickly and cheaply, then posts a summary back to Ethereum for safety.
In March 2024 the Dencun upgrade added blobs, a cheaper way for layer 2 networks to post their data. As a result, using a layer 2 became far cheaper. In mid-2024 US spot ether ETFs also began trading, giving investors a new way to get exposure without holding ether themselves.
Remember: Ethereum scaled by letting other networks do the busy work on top of it.
Lesson 3: Pectra, Fusaka and what is next
The Pectra upgrade activated on 7 May 2025. It increased blob capacity and added features that let ordinary accounts behave more like smart wallets.
The Fusaka upgrade followed on 3 December 2025. It introduced a new way of checking data so the network can handle more of it without every computer storing everything.
The next planned upgrade is called Glamsterdam. In October 2026 it began running on a public test network, but no date for the main network had been set when this lesson was checked. Upgrade dates often move, so check an up-to-date source. As always, this is history and education, not financial advice.
Remember: Upgrades keep coming, and their dates can slip.
Key dates
When
What happened
Why it matters
15 September 2022
The Merge: Ethereum moves to proof of stake
Cuts the network’s energy use dramatically
April 2023
The Shapella upgrade enables staking withdrawals
People who staked can now take their ether out
March 2024
The Dencun upgrade adds blobs
Layer 2 networks become much cheaper to use
Mid-2024
US spot ether ETFs begin trading
Ether becomes available through ordinary investment accounts
7 May 2025
The Pectra upgrade activates
More blob capacity, and smart-wallet features for ordinary accounts
3 December 2025
The Fusaka upgrade activates
A new way to check data, so the network can handle more
October 2026
The Glamsterdam upgrade starts on a test network
Planned to raise the network’s capacity again; no main network date has been set
Key terms: proof of stake, validator, layer 2, rollup, blob, ETF. Open the glossary
Module quiz
4 questions. Tap an answer to see if you are right and why.
1. What changed in the Merge (15 September 2022)?
Proof of stake replaced proof of work, cutting energy use sharply.
2. What is a layer 2 network?
It posts summaries back to Ethereum for safety.
3. Which upgrade made layer 2 data much cheaper in 2024?
Dencun, in March 2024, introduced blobs.
4. What does the Merge NOT do on its own?
Cheaper fees came from later changes, mainly layer 2 networks.
Do it yourself
Pick one upgrade from the table and explain it in two sentences to a friend who knows nothing about crypto. Ask them to say it back to you in their own words.
Not financial advice. This lesson is history and education only. Prices are rounded and shown only to explain how big the swings were.