Understanding the Eth2 vision
Ethereum needs to be able to handle more transactions per second without increasing the size of the nodes in the network. Nodes are vital network participants who store and run the blockchain. Increasing node size isn’t practical because only those with powerful and expensive computers could do it. To scale, Ethereum needs more transactions per second, coupled with more nodes. More nodes means more security.
The shard chains upgrade will spread the load of the network into 64 new chains. This will give Ethereum room to breathe by reducing congestion and improving speeds beyond the current 15-45 transactions per second limit. More on shard chains
See more: Ethereum 2.0
And even though there will be more chains, this will actually require less work from validators – the maintainers of the network. Validators will only need to ‘run’ their shard and not the entire Ethereum chain. This makes nodes more lightweight, allowing Ethereum to scale and remain decentralized.
The Eth2 upgrades improve Ethereum’s security against coordinated attacks, like a 51% attack. This is a type of attack where if someone controls the majority of the network they can force through fraudulent changes.
The transition to proof-of-stake means that the Ethereum protocol has greater disincentives against attack. This is because in proof-of-stake, the validators who secure the network must stake significant amounts of ETH into the protocol. If they try and attack the network, the protocol can automatically destroy their ETH. More on proof of stake
This isn’t possible in proof-of-work, where the best a protocol can do is force entities who secure the network (the miners) to lose mining rewards they would have otherwise earned. To achieve the equivalent effect in proof-of-work, the protocol would have to be able to destroy all of a miner’s equipment if they try and cheat. More on proof of work
Ethereum’s security model also needs to change because of the introduction of shard chains. The Beacon Chain will randomly assign validators to different shards – this makes it virtually impossible for validators to ever collude by attacking a specific shard. Sharding isn’t as secure on a proof-of-work blockchain, because miners can’t be controlled by the protocol in this way.
Staking also means you don’t need to invest in elite hardware to ‘run’ an Ethereum node. This should encourage more people to become a validator, increasing the network’s decentralization and decreasing the attack surface area. More on nodes
You can become a validator by staking your ETH.
Maybe you are interested: ETH vs. ETC: What is the difference between Ethereum and Ethereum Classic?
Ethereum needs to be greener.
It’s no secret that Ethereum and other blockchains like Bitcoin are energy intensive because of mining. More on mining
But Ethereum is moving towards being secured by ETH, not computing power – via staking. More on staking
Although staking will be introduced by the Beacon Chain, the Ethereum we use today will run in parallel for a period of time, before it ‘merges’ with the Eth2 upgrades. One system secured by ETH, the other by computing power. This is because, at first, shard chains won’t be able to handle things like our accounts or dapps. So we can’t just forget about mining and Mainnet.
With the Beacon Chain up and running, work has begun on merging Mainnet with the new system. This will turn Mainnet into a shard so that it’s secured by ETH and far less energy intensive.