DisplayPort is an interface standard without any fee for using. It seems that HDMI and DisplayPort have the same function and with a high speed digital serial links.  

In fact, they are completely different on structure. 

On Physical properties, HDMI and Display Port both are based on same infrastructure and used high-speed low voltage differential signal to transmit data when they run on differential coaxial twisted-pair cable. 

But the similarities end there. Although their standards are very similar from the appearance, a great deal of difference on structure. 

Their difference determines the performance of the link cost, compatibility, robustness and easy execution ability.

HDMI standard defines four types of connectors, A to D. In addition to the Type B, the rest are 19 pin. Type C and D are used for small equipment and portable applications.

Two standard cables are slightly different. 

1. HDMI1.0 to1.3 use four pair shield coaxial on differential coaxial, four single-ended control signal , power supply (+ 5 v) and drain. 

2. HDMI1.4 increased the audio return channels and Ethernet, so the fabric of the signal is different. HDMI1.4 uses four pairs coaxial, one unshielded differential pair, three single-ended signal, power supply (+ 5 v) and drain. This means that, HDMI1.4 and HDMI1.3 use different cables. If using a non HDMI1.4 cable in HDMI1.4 system, the audio return and Ethernet function will be lost. However, all function of HDMI1.3 and other new features of HDMI1.4 (such as 3D) can be kept.

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