???? Layers inside of the blockchain architecture.

Blockchain architecture. It is an ecosystem that includes components and subcomponents or layers that make up a complete blockchain system.?

Because blockchain eliminates intermediaries, lowers costs and is transparent, yes, it lacks centralized authority. At the same time, the decentralized nature enhances certain aspects of security (immutability and resistance to single points of failure), yet introduces some risks (smart contracts bugs or 51% attacks).?

The system also needs to be extremely scalable to handle increasing users, transactions and other data. This mostly relates to public blockchains. In private blockchains, scalability is managed way easier as less nodes participate in consensus (explained a bit lower) and because less computationally intensive consensus mechanisms are used (also explained even lower).?

“Scalable” means a growing number of throughput (transactions per second) and reduction of latency (confirmation time) while maintaining decentralization and security.?

Back to what makes blockchain complete: layers.?

The point of a layer is multilateral:

1. Store data?
2. Ensure consensus across the system
3. Maintain network connectivity
4. Transaction validation.

Depends on what exactly this or that layer was built for (by developers, researchers, organizations, or open-source communities).

Let’s sort out types of blockchain architecture.?

Public blockchain: open to everyone, permissionless. A variety of consensus mechanisms are allowed there.?

?? “What is consensus and consensus mechanism, or is it the same thing?”. Ok, as promised:

Consensus is a collective agreement among the majority (or all) nodes (transaction participants) within a network on the validity of a transaction or the current state of the blockchain.?

A consensus mechanism is a protocol that allows those participants (nodes) to agree on the transaction, and the current state of the blockchain, as a whole. (PoW, PoS).?

Back to PB: However, when it comes to scalability in public blockchains, it’s a bit of a problem due to an endless increasing demand for transactions.?

Private blockchain: permission needed, perfect for enterprises and business organizations.?

Hybrid blockchain: combines advantages of both - public and private blockchains.?

Consortium blockchain: perfect for partnership, meaning formed by several private nodes, or as we already know, transaction participants.?

Commonly used model includes Layer 1, Layer 2, Layer 3.?

Extended model: up to 5 layers.?

Moreover, an optional Layer 0 exists which represents an underlying ecosystem that enables blockchain communication (hardware (data centers) and inter-network communication capabilities)). May involve general internet protocols TCP/IP.?

Layer 1: Base Layer - the blockchain network, including consensus mechanisms, transaction processing, primary ledger.?

Layer 2: Off-Chain Scaling Solutions - built on top of Layer 1, enhances scalability, reduces congestion (delays, high costs).??

Layer 3: Application Layer - the development of smart contracts, decentralized apps, NFT platforms, wallets, social media apps, and others.?

Layer 4: User Interaction (UI) Layer (also optional) - needed for user interfaces and APIs to maintain interaction with Layer 3 apps.?

?? “Is that it?”

If you dig deeper, you will bump into Hardware Layer, Data Layer, Network Layer, Consensus Layer which are subcomponents within broader layers of the blockchain architecture that explain different functionalities that make up the blockchain stack.?

Hope it answers some questions and is beginner-friendly enough. If not, you already know what to do: stop being a beginner. ??