The Runtime hosts the Trillo applications including those which are headless. It is comprised of two tiers of services namely "web" and "data" tier. As the name implies, web tier renders the frontend of the application. Depending on the application, an end-user may be asked to log in or signup. A single web tier can host several applications.
Data tier, also called data service, is isolated from the end-user and can only be accessed by the web tier. It provides access and connection to a wide variety of data sources in the data lake.