About a year ago I bought a modestly inexpensive USB-C hub at one of the major chains (the one with the red circle). It has two USB-C ports and three of the more common USB-A ports. One of the USB-C ports is actually a short cable with a USB-C male connector at the end; this cable normally connects to a computer. The other USB-C port is a female with no cable. It was supposed to be possible to connect this port to the USB-C power supply that came with the computer, to charge the computer through the hub. But this turned out not to work. The part that was more bothersome, though, was that this USB-C port was usable for certain kinds of data transfer, notably for connecting an external DVD/Blu-ray drive, but for whatever reason was not usable for connecting the iPhone. I could charge the iPhone using this port, but the iPhone wouldn't show up in Finder on the computer, and this meant that the ordinary synchronization, back up and data transfers between the computer and the phone were not supported by the USB-C hub.This struck me as kind of weird given that I was able to charge the phone through this USB-C port. I have since spent some time studying the specifications for a half-dozen different USB-C hubs sold on Amazon, and have discovered that this is apparently how virtually all of them work, including the fancy ones that sell for $100 or more. The expensive ones have some bells and whistles that I don't need and that I do not want to pay for. For my purposes, they are not more useful than the minimal Anker USB-C hub that I bought locally at the red circle store about a year ago. From what I recall it only cost about $30. At that time I was using a 'droid phone (LG), which used an included cable with USB-A at one end and some tiny, unusual type of USB connector on the end that connected to the phone. With that phone, I could do everything that the phone was capable of doing with the computer, using one of the three USB-A ports on the so-called USB-C hub. There was no problem with that. So what exactly was the reason why the new iPhone that I bought, when connected to the spare USB-C port on the hub, would not do anything except allow the battery to charge? Was this due to a difference in the iPhone vs. the LG 'droid, or was it due to a difference in the hub's USB-A ports and its spare USB-C ports?It turns out that the so-called USB-C hub was the problem, and it looks like virtually all of the USB-C hubs have this same problem. I do not know why, but even though these hubs connect to your computer's USB-C port (which is the only reason they call them "USB-C hubs"), and even though the spare USB-C port on these hubs will charge the phone and are usable for connecting monitors (apparently) and for connecting external optical drives, and are possibly usable for connecting external hard drives (I have not confirmed this), they do not support the type of data exchange that ordinarily is needed when an iPhone is connected to that spare USB-C port. It doesn't seem right to me that they should call these hubs "USB-C hubs" given that they have this limitation. And this limitation is not something that is inherently about USB-C vs. USB-A connectors. It has to be attributable to the way the hubs are designed, internally. I haven't taken the time to look into that, but the point is that while it seems that you should be able to connect your phone to the spare USB-C port on the hub and do what you need to do between the phone and the computer, all you can do with the phone connected to the spare USB-C port is charge the phone.The temporary workaround was to free up one of the two USB-C ports on the computer, either the one I normally use for connecting the computer to the USB-C power supply that keeps the computer's battery charged, or else the other one that the hub is normally plugged into. When I disconnect the hub, the wireless, USB-A mouse doesn't work, but I don't much mind using the track pad. But, the hub has three USB-A ports, and when I was using that other phone, I didn't have any problems of any sort with the hub's USB-A ports. Nor did I ever have any other problem of any sort with those three USB-A ports, when connecting any other type of device.This raised the obvious question of whether the solution would be as simple as sticking one of those little USB-A to USB-C adapters into the USB-A ports on the hub. When I searched for USB-A to USB-C adapters, I found very many of the wrong type, with used a cable, and which had a male USB-C connector at one end and a female USB-A connector at the other end. I'm sure that these are useful for certain scenarios, particularly for connecting an external device that came with a standard USB-A connector at the end of a cable, to a computer than has only USB-C ports. But this is the reverse or inverse of the solution that it needed if you have a phone with a cable that has a male USB-C connector, and want to connect it to the USB-A port on a hub (or to an older computer with only USB-A ports). For my scenario, I needed a little thing that looks sort of like a thumb drive, that at one end has female USB-C just like the USB-C ports on the computer (and like the spare USB-C port on the hub), and that, at the other end, has a male USB-A connector that will allow me to connect it to the USB-A ports on the hub. I bought a package of two very inexpensive ones, and they work PERFECTLY. One of them stays in one of the USB-A ports on the hub, and this is what I use when I want to connect the iPhone to the computer in order to synch the phone and so on, and it also charges the phone from the computer. 100% functionality. The other one is inserted into the USB-A charger from the older phone, and using this, I am able to use that older charger to charge the new i-Phone.So this turned out to be solution. In effect, it turned the not-truly-a-USB-C-hub into a truly-a-USB-C-hub. A very cheap and easy solution. But it raises a question. Given that this worked, it is obvious that the manufacturer of the so-called USB-C hub (Anker) could easily have made the spare the USB-C port on the hub work the way it ought to work. In the write-ups that Anker and the others place on their Amazon pages, they are careful not to mention this limitation and not to say anything that might cause you to suspect that the spare USB-C ports on the hub have this weird limitation. I think that's a little deceptive. They should say plainly that the things have this limitation. But the weird thing is that they have this limitation, given that the simple solution renders apparent the fact that their isn't any real reason for them to have this limitation. It is manifest that they could wire the spare USB-C port the same way that the adapter is effectively wired when it is inserted into the hub's USB-A port. This is just plain weird. All of these USB-C hubs are being manufactured with this same limitation even though there isn't any reason at all for them to have this limitation. All I can figure is that they are all using the same little circuit boards and this circuit board was designed by someone who didn't quite understand how the thing being designed should work. I just don't know how to explain it.The bottom line is that if you need a USB-C hub because you've bought a new computer that has only USB-C ports, go ahead and buy one that has what you think you need, however (1.) do not expect to be able to charge your computer through the hub no matter if the specifications claim that you can do this, and in fact don't even try to do this because you're likely to burn up the hub if you try it, and (2.) when you buy the hub, go right ahead at the same time and buy a pair of these little adapters that you can stick into the USB-A ports on the hub to turn them into properly functioning USB-C ports, because the spare USB-C port on the hub is most likely not going to be a fully functioning USB-C port.