Developers may manage and share common code and dependencies across several Lambda functions with the aid of AWS Lambda layers, a significant tool. They serve as a means of distributing libraries, unique runtimes, and other function requirements, enabling you to maintain the organization and light weight of your deployment packages.

In essence, a Lambda layer is a ZIP archive containing configuration files, libraries, or unique code. This layer can be connected to one or more Lambda functions after it has been constructed. AWS automatically combines your function code in the /opt directory with the content of all attached layers while the function is running. This configuration is perfect for sharing functionality, such as external packages or utility functions, without having to duplicate code in each function.

Each Lambda function can have up to five layers, and versioning for each layer can be controlled independently. This makes it easier to update across functions and allows for improved version management.

For instance, you can include an external library (such as requests) in a layer rather than packaging it separately with each function if you're creating several Python AWS Lambda functions that require the same library.

In cloud-native applications, layers aid in reducing redundancy, accelerating deployment, and improving maintainability.