What Is Layer 2s and Why Do We Need Layer 2s

Layer 2 solutions have the potential to be the next big thing in the blockchain industry, providing a new frontier for scaling and improving the efficiency of decentralized applications. These solutions are becoming increasingly important as the demand for decentralized systems grows, pushing the limits of current blockchain infrastructures.

In this article, we will look at the fundamentals of Layer 2 solutions, their advantages, and how they are expected to change the blockchain landscape.

What Is Layer 2s?

Layer-2 solutions are off-chain protocols that are built on top of existing blockchain infrastructures and provide a way to improve the scalability, speed, and efficiency of decentralized applications. These solutions process transactions off-chain before batching and committing the result to the blockchain which helps to reduce blockchain congestion and transaction fees. State channels, plasma chains, rollups, and side chains are all examples of Layer 2 solutions.

Another example of a Layer 2 solution is the Lightning Network, which is a state channel that is built on top of the Bitcoin blockchain.  The Lightning Network enables near-instant, low-cost transactions between two parties without the need for main chain conformations.

Why Do We Need Layer 2s

Here are some of the reasons for the need for Layer 2 solutions, as well as some of the limitations of Layer 1:

What is the purpose of Layer 2 solutions?

  • Scalability: Layer 2 solutions can help blockchains significantly increase their capacity, allowing them to handle a higher volume of transactions.
  • Flexibility: Layer 2 solutions provide a variety of approaches and techniques that can be adapted to the requirements of specific use cases and applications.
  • Speed: Layer 2 solutions can improve the speed and efficiency of blockchain networks by processing transactions off-chain.
  • Cost: Layer 2 solutions can help to reduce transaction fees by reducing the load on the main blockchain, making blockchain technology more accessible and affordable.

What were Layer 1's limitations?

  • Scalability: Layer 1 blockchains, such as Bitcoin and Ethereum, have limited transaction processing capacity, which can result in congestion and higher fees.
  • Interoperability: Layer 1 blockchains are not always compatible with one another, which makes developing decentralized applications that can interact with multiple blockchains difficult.
  • Speed: Transactions on Layer 1 blockchains can be slow, especially during times of high demand.
  • Cost: Due to the limited capacity of Layer 1 blockchains, transaction fees may be higher, making blockchain technology less accessible and affordable.

Types of Layer 2s

  1. Zero Knowledge Rollups: ZK-rollups use zero-knowledge proofs to enable off-chain transaction processing while maintaining the blockchain's security and trustworthiness.
  2. Optimistic Rollups: Optimistic Rollup is a Layer 2 scaling solution that processes transactions off-chain and by default assumes they are valid. It provides faster and cheaper transaction processing while maintaining the underlying blockchain's security and trustlessness.
  3. Plasma: Plasma is a Layer 2 framework that processes transactions off-chain using sidechains. Plasma allows users to create "child chains" that are linked to the main chain, allowing for quick and inexpensive transactions.
  4. State channels: Allow users to conduct off-chain transactions without requiring the blockchain to validate each transaction. Users can instead sign transactions off-chain and then submit them to the blockchain when they are ready to settle.

How Does Layer 2s Work?

Layer 2 solutions reduce network congestion and increase throughput by processing transactions off-chain, away from the main blockchain. These transactions are then submitted to the main chain for verification, ensuring the blockchain's security and trustworthiness. A popular Layer 2 solution, Optimistic Rollup, assumes the validity of transactions by default and only submits evidence to the main chain in the event of a dispute. This method allows for faster and less expensive transaction processing while maintaining the underlying blockchain's security and decentralization.

Advantages of Layer 2s

Layer 2 offers several advantages over layer 1:

  • Scalability
  • Lower Fees
  • Faster Transactions
  • Improved User Experience
  • Easier Development

Disadvantages of Layer 2s

Some potential disadvantages of Layer 2 scaling solutions include:

  • Centralization
  • Complexity
  • Limited Use Cases
  • Interoperability
  • Security Risks


Finally, Layer 2 scaling solutions are a new approach to overcoming the scalability and efficiency limitations of traditional Layer 1 blockchains. Layer 2 solutions can significantly increase transaction capacity, reduce fees, and improve overall user experience by moving some transaction processing off-chain and leveraging different consensus mechanisms. While Layer 2 solutions are not without challenges and limitations, they do provide a promising path toward making blockchain technology more accessible and practical for a broader range of use cases and industries.

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