With AWS Lambda, you can run code without provisioning or managing servers. You pay only for the compute time you consume—there’s no charge when your code isn’t running. You can run code for virtually any type of application or backend service—all with zero administration. Just upload your code and Lambda takes care of everything required to run and scale your code with high availability. You can set up your code to automatically trigger from other AWS services or call it directly from any web or mobile app.

Developer Guide
Provides a conceptual overview of AWS Lambda, includes detailed instructions for using the various features, and provides a complete API reference for developers.
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