Create an External Source
Providing your Sitecore-powered website visitors with a means to search across the website and other information repositories through a single Coveo for Sitecore search interface can save them a significant amount of time. This entails that you must first index those other information repositories (i.e., external sources) by creating a source through the Coveo Administration Console.
Coveo provides a wide array of connectors that let you establish a connection with a specific content type. Sometimes, several connectors can be used for the same content type. You might, therefore, have to decide upon the best connector to use (see Prepare for Indexing).
You can then refer to the documentation article on how to add a source using the selected connector. These connector-specific articles are located in the Connector Directory.
Several indexing techniques can be used to refine/enhance content prior to, and during the indexing process.
You will want to apply one or more of these techniques to eliminate useless data from your source and to minimize your number of indexed documents, as your Coveo for Sitecore license includes an
External Source Indexing restriction (see Apply Indexing Techniques).