The Connector Tool is most valuable when you already have other elements on the Drawing Canvas. Click the Connector button in the toolbar and connection points will appear on any symbols on the Drawing Canvas. Connect any two of these connection points with a click-drag, release. To change the style settings, click the connector and open the blue properties menu.

Unlike the Connector tool, the Straight Line Tool will only draw a perfectly straight line, with no bends or corners. But you can still use it to link connection points on symbols, if a perfectly straight line is appropriate for your diagram. Click the Straight Line Tool button in the toolbar and draw a line with a click-drag, release. You can also connect any two connection points with a click-drag, release. To change the style settings, click the line and open the blue properties menu.