What is this thing? Should I use it?

[serilex]

This came with something in my build. It looks as if it has a hdmi blue thing on it, and it connects to the dvi-d or the dvi-i slot. Should I use it? Is it important?

Hope the image is clear enough

http://imgur.com/N6NvtLR

 

[carlo_bigtunes]

that thing is d-sub to dvid converter
a monitor above 19" only have d-sub cable

 

[serilex]

that thing is d-sub to dvid converter
a monitor above 19" only have d-sub cable

My monitor is 23". Should I use it? And where should I use it, if at all?

 

[duxducis]

that thing should newer be used, unless you got ancient monitor and want bad video quality
All newer monitors and tvs have HDMI and DVI ports witch is the best

old D-sub blue on your picture is from past, hide it away

 

[Ra_V_en]

lol at up... first and the most important difference: D-SUB is an analog connector and if used will drop the display quality, so avoid as much as you can. DVI/HDMI are digital connectors which should be used instead.

"that thing is d-sub to dvid converter
a monitor above 19" only have d-sub cable"

If you live in a 3-rd world country than maybe its true, otherwise all of current monitors use DVI. Only a few old TV displays and very old monitors use D-SUB. Some monitors can still have both (due to compatibility) but again avoid the old socket.