Yes I googled, but it’s mostly about the actual ports and not the cable. And Apple’s support wants you to buy their branded cable. Amazon or Monoprice preferred.
Macbook Pro has a port with the lightning bolt next to it (Thunderbolt). This is physically identical to mini DisplayPort. If I want to connect it to a TV through HDMI, and preferably play audio through the TV, which cable do I buy:
Thunderbolt vs. mini DisplayPort vs. it doesn’t matter, the internals are the same. The former is more expensive. Yes, I realize I’m quibbling about a few dollars.
Active vs. passive. The former is only useful if I have multiple devices?
If there is a difference in #1, how do I trust a random seller to make a distinction?
If all you are interested in is the video signal, you can buy any old mini Displayport cable.
If you want to use the Thunderbolt part of the connector, you need to buy a Thunderbolt cable, which are all active.
If you buy a Thunderbolt/HDMI adapter, it’s almost certainly a DP++/HDMI adapter, which they are calling “Thunderbolt (DisplayPort)” if they are reputable, or just “Thunderbolt” if they aren’t worried about their reputation, or “DisplayPort” if the page has been up for a while.
The internals aren’t the same. The Thunderbolt cable has to include the Thunderbolt chips: the DisplayPort cable won’t include the Thunderbolt chips.
All Thunderbolt cables are active, because the system was designed to use optical cables with the optical converters in the cable ends. The new Thunderbolt 3 system will allow passive cables.
DP can be active (to get longer cable runs). As I understand it, the MacPro Thunderbolt socket includes one DP++ signal, which you may connect a passive DP cable to, which you may connect to a “passive” DP/HDMI adapter.
Because the DP and Thunderbolt cables are different things, I don’t think you’ll have trouble with one being passed of for the other. I haven’t seen any cable called “Thunderbolt (DP)” or “DP (Thunderbolt)”, but if I did, I would avoid it: there is enough confusion already.
You can put multiple different pictures onto a Thunderbolt cable string. (I think the MacPro video card supports that kind of thing).
You can put multiple different pictures on to DP monitors using true Thunderbolt - Display Port adapters, to pull the multiple pictures out of the Thunderbolt signal.
You can put one single DP picture onto multiple displays using an active DP multiple-monitor adapter. You can also buy special equipment that recalculates the picture to split the picture up between multiple displays.
You can get one DP picture out of a Thunderbolt socket which supports DP++. It’s got an internal Thunderbolt-DP converter, to put the DP signal out as well as the Thunderbolt signal. I think the MacPro does this.