Connection
A Connection (pushtopics__Connection__c) defines the authentication configuration used to connect to a Salesforce org. A Connection can act as:
A Source for retrieving data
A Target for performing actions
Authentication Flow
Data Sync Pro handles authentication through two paths, decided at runtime based on the Is Current Org flag on the Connection record.

Current Org: Runs as the currently logged-in user, requiring no additional credentials.
OAuth 2.0 (Refresh Token Flow): Authenticates through a Named Credential using an OAuth token issued through the Refresh Token flow.