A runtime environment is an execution environment for deploying and running applications. Runtime environments contain the necessary applications, dependencies, and operating system to run an application. For example, when you create an app on App Platform, App Platform inspects the code and app resources, and then selects the appropriate runtime environment, such as Node, to run the app in.
Runtime environments are containerized. Containerization creates consistent and isolated runtime environments, ensuring application portability. Preconfigured runtime environments support multiple programming languages and frameworks, eliminating the need for manual setup.