What is VGA and HDMI cable?

VGA and HDMI are interface standards used for cables that connect devices — such as laptop computers and DVD players — to a display, like a TV, computer monitor or projector.

HDMI:

HDMI (High-Definition Multimedia Interface) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from an HDMI-compliant source the device, such as a display controller, to a compatible computer monitor, video projector, digital television, or digital audio device. HDMI is a digital replacement for analog video standards.

The HDMI standard allows for the transfer of both digital video and audio signals via the same interface (port) and cable, capable of providing high-definition (HD) video at resolutions of 1,920 x 1,200 pixels and 8 audio channels simultaneously. Because it supports digital copy protection of all signals, HDMI cables are included for devices such as the Apple TV, Blu-Ray players, and game consoles, among other similar electronic products.

Pin ut

HDMI type A receptacle
Pin 1	TMDS Data2+
Pin 2	TMDS Data2 Shield
Pin 3	TMDS Data2−
Pin 4	TMDS Data1+
Pin 5	TMDS Data1 Shield
Pin 6	TMDS Data1−
Pin 7	TMDS Data0+
Pin 8	TMDS Data0 Shield
Pin 9	TMDS Data0−
Pin 10	TMDS Clock+
Pin 11	TMDS Clock Shield
Pin 12	TMDS Clock−
Pin 13	CEC
Pin 14	· Reserved (HDMI 1.0–1.3a) · Utility/HEAC+ (HDMI 1.4+, optional, HDMI Ethernet Channel and Audio Return Channel)
Pin 15	SCL (serial clock for DDC)
Pin 16	SDA (serial data for DDC)
Pin 17	Ground (for DDC, CEC, ARC, and HEC)
Pin 18	+5 V (min. 0.055 A)
Pin 19	· Hot Plug Detect (all versions) · HEAC− (HDMI 1.4+, optional, HDMI Ethernet Channel and Audio Return Channel)

VGA:

VGA connectors and cables carry analog component RGBHV (red, green, blue, horizontal sync, vertical sync) video signals and VESA Display Data Channel (VESA DDC) data.

A Video Graphics Array (VGA) connector is a three-row 15-pin DE-15 connector. The 15-pin VGA connector was provided on many video cards, computer monitors, laptop computers, projectors, and high definition television sets. On laptop computers or other small devices, a mini-VGA port was sometimes used in place of the full-sized VGA connector.

VGA is an older standard that carries only a video signal. HDMI is the default cable standard for newer electronic devices, such as Blu-Ray players or LED TVs. HDMI can carry both digital video and audio signals, all while encrypting data with HDCP.

The video quality attained with a VGA cable is noticeably worse when compared to that of HDMI.

in out

A female DE15 socket.
Pin 1	RED	Red video
Pin 2	GREEN	Green video
Pin 3	BLUE	Blue video
Pin 4	ID2/RES	Reserved since E-DDC, formerly monitor id. bit 2
Pin 5	GND	Ground (HSync)
Pin 6	RED_RTN	Red return
Pin 7	GREEN_RTN	Green return
Pin 8	BLUE_RTN	Blue return
Pin 9	KEY/PWR	+5 V DC (powers EDID EEPROM chip on some monitors), formerly key
Pin 10	GND	Ground (VSync, DDC)
Pin 11	ID0/RES	Reserved since E-DDC, formerly monitor id. bit 0
Pin 12	ID1/SDA	Data since DDC2, formerly monitor id. bit 1
Pin 13	HSync	Horizontal sync
Pin 14	VSync	Vertical sync
Pin 15	ID3/SCL	Clock since DDC2, formerly monitor id. bit 3
The image and table detail the 15-pin VESA DDC2/E-DDC connector; the diagram’s pin numbering is that of a female connector functioning as the graphics adapter output. In the male connector, this pin numbering corresponds with the cable’s wire-and-solder side.

VGA vs. HDMI Capabilities:

HDMI is a digital cable. VGA is analog. VGA cables can have degrading quality within the cables and make picture quality poorer. On the other hand, HDMI is all digital, so quality is not at all affected. HDMI either works entirely or doesn't work at all. This is also why overpriced HDMI cables aren't worth it. There is no picture quality difference whatsoever. Sometimes you might want a better HDMI cable if it's moved a lot and needs to be more rugged, but otherwise its best to get the cheapest one. VGA is more hit and miss.