porter/docs/deploy/applications/overview.md

There are three types of applications you can deploy on Porter: web services, workers, and cron jobs. Below is an overview of each application type as well as the use cases each one is best suited for.

Web Service

Web services are processes that are constantly running and are exposed to either external or internal traffic. This includes any servers or web applications - most of your deployments should fall into this category.

You can choose to expose your application to external traffic on a custom domain - Porter will automatically secure your endpoints with SSL certificates. Alternatively, you can expose your web service to only internal traffic (i.e. accessible only by other deployments in the same cluster).

Worker

Worker processes are constantly running processes that are exposed to neither external nor internal traffic. Workers have no URLs or ports - it's best suited for background processes, queuing systems, etc.

Cron Job

Jobs are one-off processes that run to completion. It's best suited for ephemeral tasks such as database migration or clean up scripts.

Cron jobs run periodically on a schedule specified as a cron expression. Please see this article for a quick guide on cron expressions. To create cron expressions more easily, try this online editor to generate cron schedule expressions.