Logitech brio 4K
There is a lot of great info in this thread, @woland gave a great response, and I wanted to add a few things to the information.
The extension options you choose will also be directly related to the bandwidth you are sending, and nothing is for free. signals sent over Ethernet extension systems will be quite limited in bandwidth, so even the mid to high tier HDbaseT extensions will make some sacrifice at higher resolutions- this is often in the form of shorter transmission distances (most 4K HDBaseT extenders drop their transmission distance a fair bit at 4k vs HD), and colour compression, most HDBaseT systems use 4:2:0 colour compression at pretty much all resolutions. This allows the manufacturers to use slower transmission and reception chips that are cheaper but can pass less bandwidth per second. This is where the high end expensive extension systems come into play. The other feature that the fancy HDBaseT stuff has is that it also modulates a network signal in the same extension over a single cable, this means when working with projectors that have a network port you can run a single cable and get signal and control.
Also on the topic of ethernet and bandwidth, AFAIK there are no full bandwidth USB 3.0 over ethernet extension systems, standard ethernet cabling cannot support that much data. So in the case of @Bennnid and the logitech camera, if you use an extension system via ethernet you will be locked to USB 2.0 speeds and not be able to capture at 4k. USB 3.0 is still difficult to extend, there are some active extensions, some fibre based cables, these are all a bit problematic in my experience - fragile cables, expensive and not repairable. There are some full bandwidth USB 3.0 over fibre extension systems (newnex) that work well but they are expensive (upwards of €1000 for the boxes and cables). There are also a lot of extenders for USB 3.0 that support the protocol but not the bandwidth - this is a kind of cheap trick, again using slower transmission modulation chips that cannot deal with things like real time video. You will see your device when it is connected but speed will be slow and in the case of video it will choke on high bandwidth streams, or not initialise. So far it is often cheaper to use an NUC close to the USB 3.0 device and stream the data you need over a standard network in some way. Having said that I am currently using/testing some cables I got from a Chinese manufacturer that are giving me full bandwidth USB 3.0 (I am using kinect Azures and they are sensitive to errors as the data streams need to be assembled via timestamp) over 25m for around €100 per cable. BTW the cable that @gapworks linked to above is USB 2.0 only, so again limited bandwidth.
To a large degree you do get what you paid for. The very expensive extension sets for HDMI over ethernet (or HDBaseT) will be able to transmit longer and are more stable, same goes for USB 2.0 over ethernet. I have been working in a space with Ethernet connections in moving trusses and patch panels throughout the room - some of the points are quite far apart (up to 75m), the cabling was done with high quality shielded cat 7 and the patch panels and cabling are high quality. We have been going through extension systems and checking their performance, and from what we see, the very expensive kits are the only ones that actually let us patch to and from anywhere in the room. The units that fail do communicate as to their spec but can only operate at lower bandwidth (of course we also check with other cables). At shorter distances the high end systems are overkill, but as soon as you need a longer distance you are forking out ~1k for an extension set.
To reiterate one of @Woland 's points - cabling becomes very important. Not all cable is equal, 2 cables specd the same can give different results so test test test, especially Ethernet and especially at higher bandwidths.