Scale Ethereum Blockchain technology

 1. Goal of scalability

• Reduce the cost of using the network (blockchain has reached certain capacity limitations).
• Increase transaction speed (faster finality), and transaction throughput (high transactions per second), without sacrificing decentralization or security.

2. Two main solution to scale Ethereum blockchain

👉 ON-CHAIN SCALING (Sharding): 

• Requires changes to the Ethereum protocol (Mainnet - layer 1).
• Splitting the blockchain into discrete pieces (shards) to be verified by subsets of validators.

👉 OFF-CHAIN SCALING:

• Layer 2 scaling: derives its security and handling transactions off from Mainnet Ethereum, centered around a server or cluster of servers (referred to as a node, validator...) Transactions are rolled up into a single transaction to Mainnet Ethereum. it's two types of rollups with different security models: Optimistic rollups and Zero-knowledge rollups.
• State channels: use multisig contracts to enable participants to transact quickly and freely off-chain, then settle finality with Mainnet.
• Sidechains:  an independent EVM-compatible blockchain which runs in parallel to Mainnet, compatible with Ethereum via two-way bridges, run under their own chosen rules of consensus, and block parameters.
• Plasma: is a separate blockchain that is anchored to the main Ethereum chain uses fraud proofs.
• Validium: uses validity proofs like zero-knowledge rollups but data is not stored on the main layer 1 Ethereum chain.