Devfine environment variable such as $PORT to seperate configuration from your codebase. Useful for configuring database connections for seperate environments (test, staging, production).
An abstract way of refering to the compute resources assigned to your app. Heroku is a lightweight container-based system, avoiding the need for you to manage and maintain servers.
A process is defined as either a web process that listens to incoming requests, or any other type you wish to define.
A simple text file that defines how to run each processes in your Heroku application
A bundle of your source, fetched dependencies, the language runtime, and compiled/generated output of the build system, ready for execution