That depends on what source your talking about.
Cable call you cable provider and ask them for a HDTV box
Satalite you should already have one if not ask them.
OTA =over the air you need a digital tuner with a nice antenna I suspect this has a digital tuner inside so all you need is a good antenna.
DVD= hook the DVD up with the red,green,blue cables called SCART connections..
Blueray= Will bring you high def.. with its connections.
So your question is vague and can be answered in so many ways.. Rate me please Btw, I’m available to help over the phone in case u need at
https://www.6ya.com/expert/edwy_1a56970cf1ea4620