Content Delivery functionality consists of a number of Server Roles. We distinguish between core Server Roles, which are always needed to get the product up and running, and nonessential features, which you may or may not install based on business needs.
Core Server Roles
The core Content Delivery Roles are:
| Role | Description |
|---|
| Discovery Service | Exposes the Discovery Endpoint, through which all Content Delivery services are made available. |
| Content Service | Exposes a number of core Content Delivery APIs. |
| Content Deployer | Deploys content published from Content Manager. |
| Search | Enables search functionality on Content Delivery-based websites. |
Nonessential Server Roles
The nonessential Server Roles are:
| Server Role | Description |
|---|
| Context Engine | Enables the discovery of, and ability to respond to, contextual information about the visitors of your website, and about the devices they use. |
| Contextual Image Delivery | Enables request-time image transformation on the published website. |
| Context Expression Extension | Makes campaign management and analysis data, compiled by SDL Campaigns available for use on your SDL Knowledge Center-based website. To use the Context Expression Extension, you must have an integration with Campaigns set up. |
| User Generated Content (UGC) | Enables commenting and rating on the published website. |