Lightning Connect (now known as Salesforce Connect) is a feature in the App Cloud that enables you to integrate external data sources with Salesforce.

Lightning Connect (now known as Salesforce Connect) is a feature in the App Cloud that enables you to integrate external data sources with Salesforce. Salesforce will connect to other Salesforce orgs and other databases to create OData 2.0, OData 4.0 and custom Data Services which appear in the UI as External Objects. In addition to providing out of the box OData Connectors, Salesforce Connect provides a Connect API that allows developers to create custom Apex Adapters to integrate Salesforce with most any API on the Internet.