The Details tab of the 'Create Connection' dialog provides information about the source and destination components, including the component name, the component type, and the Process Group in which the component lives:
Additionally, this tab provides the ability to choose which Relationships should be included in this Connection. At least one Relationship must be selected. If only one Relationship is available, it is automatically selected.
If multiple Connections are added with the same Relationship, any FlowFile that is routed to that Relationship will automatically be 'cloned', and a copy will be sent to each of those Connections.