does any one know what is HDMI?

HDMI (High-Definition Multimedia Interface) is a compact audio/video interface for transmitting uncompressed digital data. RCA cables however transmits in analog.

I never really studied that particular feature on computers, but its basically a lot better than something like VGA, if I'm wrong on the name, correct me, I don't study cables lol. Anyway, it allows your computer to display the screen on either a TV or monitor that supports the HDMI port. I used it for my laptop on my TV in my basement. Works pretty well. And you don't have to screw anything in.

HDMI (High-Definition Multimedia Interface) is a compact audio/video interface for transmitting uncompressed digital data.[1] It represents a digital alternative to consumer analog standards, such as radio frequency (RF) coaxial cable, composite video, S-Video, SCART, component video, D-Terminal, or VGA. HDMI connects digital audio/video sources—such as set-top boxes, upconvert DVD players, HD DVD players, Blu-ray Disc players, AVCHD camcorders, personal computers (PCs), video game consoles such as the PlayStation 3 and Xbox 360, and AV receivers—to compatible digital audio devices, computer monitors, and digital televisions.[1] HDMI supports, on a single cable, any uncompressed TV or PC video format, including standard, enhanced, and high-definition video; up to 8 channels of compressed or uncompressed digital audio; and a Consumer Electronics Control (CEC) connection. The CEC allows HDMI devices to control each other when necessary and allows the user to operate multiple devices with one remote control handset.[2] Because HDMI is electrically compatible with the signals used by Digital Visual Interface (DVI), no signal conversion is necessary, nor is there a loss of video quality when a DVI-to-HDMI adapter is used.[3] As an uncompressed connection, HDMI is independent of the various digital television standards used by individual devices, such as ATSC and DVB, as these are encapsulations of compressed MPEG video streams (which can be decoded and output as an uncompressed video stream on HDMI). The HDMI standard was not designed to include passing closed caption data to the television for decoding.[4] So any closed caption stream has to be decoded and included as an image in the video stream(s) prior to transmission over an HDMI cable to be viewed on the DTV. This limits the caption style (even for digital captions) to only that decoded at the source prior to HDMI transmission. This also prevents closed captions when transmission over HDMI is required for upconversion. HDMI products started shipping in late 2003.[5] Over 850 consumer electronics and PC companies have adopted the HDMI specification (HDMI Adopters).[6][7][8] In Europe, either DVI-HDCP or HDMI is included in the HD ready in-store labelling specification for TV sets for HDTV, formulated by EICTA with SES Astra in 2005. HDMI began to appear on consumer HDTV camcorders and digital still cameras in 2006.[9][10][11][12][13] Shipments of HDMI were expected to exceed that of DVI in 2008, driven primarily by the consumer electronics market

Taken from Wikipedia, hope it helps :)

HDMI stands for High Definition Multimedia Interface, and it's a way of transferring video and audio signals digitally.

HDMI (High-Definition Multimedia Interface) is a compact audio/video interface for transmitting uncompressed digital data. http://electronics.howstuffworks.com/hdmi.htm