HD is the term used to differentiate the systems that generate, transmit or support HD content (High Definition) with those of standard definition or low definition (SD).

HD resolutions are usually at least 1280 x 720 pixels by taking the ratio "width x height". Being the height, 720 pixels, which make high resolution.

The English acronym "HDMi" refers to "High Definition Multimedia Interface", that is, it corresponds to the initials of high definition multimedia interface.

The HDMi interface allows the transmission of video and audio between different devices, supporting the video resolutions 480i, 480p, 576i, 576p, 720p, 1080i, 1080p, 1440p, 1600p.

Different versions of HDMi

HDMi 1.0
- December 2002.
- Maximum transfer of 4.9 Gbit / s.
- Support up to 165 Mpixels / s in video mode (1080p 60Hz or UXGA) and 8 channels / 192 kHz / 24-bit in audio mode.

HDMi 1.2
- August 2005.
- Added support for One Bit Audio, used in Super Audio CD, up to 8 channels.
- HDMi Type A availability for PC connectors.

HDMi 1.3
- June 2006
- Bandwidth at 340 MHz.
- 10.2 Gbit / s data rate.
- Dolby TrueHD and DTS-HD,

HDMi 1.4
- Send high definition video and audio,
- 3D data and video.
- FullHD to XHD (eXtended High Definition) up to 4096 × 2160 pixels (24 frames per second) or 3840 × 2160 to (30 frames per second).
- Audio return channel that will require fewer cables to have a surround sound system connected to the television.
- Ethernet connection built into the cable itself with speeds of up to 100 Mbit / s.

HDMi 2.0
- September of 2013
- Bandwidth up to 18 Gbit / s
- 4K @ 50/60 (2160p) video
- Up to 32 audio channels for a multi-dimensional immersive experience
- Up to 1536kHz audio frequency for maximum sound fidelity
- Simultaneous delivery of 2 streaming video for multiple users on the same screen
- Audio streaming up to 4 users
- Support Theater Angle 21: 9 radio
- Dynamic synchronization of video and audio in streaming
- CEC command extensions to control multiple devices from a single point.


Types of HDMi

Type A (in image 1): It is the most standard connector used in almost all devices.
Type B (in image 2): It is a very little used connector.
Type C (in image 3): It is a connector widely used in tablets, smartphones and other devices.
Type D (in image 4): It is a connector used in smartphones.
Type E (in image 5): It is a connector used in vehicle connectivity.

1080p is an alternative name for the maximum resolution used in high definition television (HDTV). The number 1080 represents 1080 lines of vertical display resolution, while the letter p stands for progressive scan and non-interlaced.

VDC would be the abbreviation for Volt Direct Current which translated would volts direct current. The idea of ??this type is unidirectional current to the load. Direct current is normally produced by batteries, thermocouples, solar cells and a dynamo electric machine type. The direct current can flow in conductors such as wires, but may also flow through semiconductors, insulators ... In the image: 1 - current per pulse 2 - Direct Current (DC) 3 - Alternating Current (AC) 4 - Variable Current

When we talk about RJ45 ("Registered Jack" 45) we refer to a telecommunications network interface for wired connection of voice and data equipment.

This connector has 8 pins or connections and may have a specific category depending on the data transfer speed and bandwidth (category 5e, 6, etc.)

The common application is their use in Ethernet network cables under TIA/EIA-568-B standard that defines the arrangement of pins (pinout), but can also be used for other applications.

- Direct pin diagram:

EIA-568A
Pin No.1: WHITE-GREEN
Pin No.2: GREEN
Pin No.3: WHITE-ORANGE
Pin No.4: BLUE
Pin No.5: WHITE-BLUE
Pin No.6: ORANGE
Pin No.7: WHITE-BROWN
Pin No.8: BROWN

EIA-568B
Pin No.1: WHITE-ORANGE
Pin No.2: ORANGE
Pin No.3: WHITE-GREEN
Pin No.4: BLUE
Pin No.5: WHITE-BLUE
Pin No.6: GREEN
Pin No.7: WHITE-BROWN
Pin No.8: BROWN

- Schematic of crossed pins:

The crossover cable has one end with EIA-568A scheme and the other one with EIA-568B.

Depending on the quality and type, network cables are classified into categories that help us know the characteristics of them.

The categories of network cables most commonly used are:

- Category 5
- Category 5e
- Category 6
- Category 6
- Category 7

As can be seen, category 5e (enhanced or improved) and category 6A (Augmented), are an improvement of categories 5and 6, respectively, which it has improved the top speed and bandwidth.

The higher the category, the higher the speed of maximum data, the maximum 100 meters distance as its standard.

You can see a table which shows the 5 categories, where V is the maximum velocity, D is the maximum and MHz frequency which can work away.