Man i am so confused. I been on forums, google and youtube. I have both headlights out. My fog lights work. High beams work. DRL lights work. I dont know if the light that is out is my low beam or called a low/high beam. I have a 2006 is350 with the lights that move up and down when you start the car. I see some people bye h11 light bulbs and some get ds4. I dont know which ones to get.

 

If your HL's lit bright and then dimmed slightly, you have HID. If not, likely a standard halogen bulb.
Remove the engine covers and pull the bulbs. If you notice a yellow high voltage sticker on the HL housing its HID. Otherwise standard. You should pull it apart before buying and check the fuses and connections to see what's wrong anyway.