There are number of ways to connect to the to your Roku Setup box.But before that you must know about the ports present on your TV.
Roku set up box gives you number of option to connect to your TV.Your TV has primarily has 3 type of ports
1.HDMI
2.Composite
3.Component
HDMI
“HDMI is known as High Definition Media Interface.Both Video and Audio signals can travel through this.”
HDMI is the most preferred way to connect to your TV.With HDMI 2.0 you can have 4K experience provided your TV also support 4K resolution at 60fps.If your TV doesn't support 4K then you can use HDMI 1.4 is the best option for you it does support 3,820x2,160 pixel resolution at 30fps.However your Roku doesn't come with the HDMI cable you have to buy it separately.
Composite
"Composite is dying technology.Video resolution degrade drastically as video signal are forced to travel through the single cable."
Composite requires the use of an analog (RCA) audio connection. Signals generally travel through the single cable and also cause of the radio frequency interface the signal degrades it does not support High Definition picture.A combination composite and analog audio cable is included with every Roku player.
Component
"Component does have HD support.But it also comprise of the analog signals. As analog signals does travel in the waveform signals are susceptible to the interface leading to the signal losses "
As Component support HD Signals these set of ports are present in almost every HDTV.This kind of port support almost every game console,Digital player,DVD player
set top boxes and Blu ray players.