AWS Lambda is a serverless platform, allowing you to execute code without the need to provision the infrastructure yourself. Code is only running when a suitable trigger is invoked, such as a hit to an API gateway, an update in DyanmoDB, or a change in an IOT device’s sensors. The code to be run is uploaded as either a .ZIP file or a container image. A variety of runtimes are available for popular languages.
Since Lambda resources are billed only when code is actively running, it can be extremely cost-effective, if a little difficult to predict.
The speed and event-driven nature of AWS Lambda makes it a great tool for building highly interactive applications. It can also be used to automate some common tasks, such as pre-prossesing data for machine learning purposes, automated backups, or coordination between other external services.