Coveo REST Search API 8.0
As shown in the following diagram, the Coveo Search API acts as a bridge between the front-end search interfaces or applications and a Coveo Enterprise Search (CES) instance maintaining a unified index on the back-end. The Coveo Search API is typically installed on the Coveo Master server, together with CES, but you can install it on any server (see Installing the Coveo Search API).
Once installed, you can configure various aspects of the Coveo Search API such as the index server, certificates, and authentication (see Customizing and Starting the Coveo Search API).