Effectively testing embedded display systems requires a clear understanding of the various interfaces which may exist in the system. This paper details the hardware interconnections used across the spectrum of these systems, in preparation for subsequent papers which describe specific test methodologies for displays. It also covers the basics of embedded display technologies and various display interface standards: VGA; Parallel (DPI); High Density Serial Links including Display Serial Interface (DSI), Flatlink (SDI), FPD-Link and Remote Frame Buffer Interface (RFB or DBI); Analog Television Interfaces such as Component Video, S-Video and Composite Video; and the Digital Television/Monitor Interfaces DVI and HDMI.