In the 21st century, the internet has ushered in almost unparalleled consumer options. No longer are you limited by what you can purchase in the US or what a US distributor is willing to import from China, Japan, Singapore or Bolivia - now you can order directly from manufacturers in those countries. This also presents a certain drawback, however, and that is little to no regulation over those goods. US importers and manufacturers are still bound by US trade laws, which includes labeling laws, but overseas manufacturers are not subject to such laws. In addition, however, even labeling laws are somewhat slack in the US when it comes to electronics. This is why it is very important to buy cables from both a reputable brand and a reputable store or distributor.
How it works
Generally, HD or "standard" HD has a display size of roughly 1,080 pixels per square inch, which is generally referred to as 1080p. 4K or Ultra HD (UHD) means it has a display size of 4,000 pixels per square inch. In addition, where video was once shot at 24 frames per second, it is now sometimes shot at 50 or 60 frames per second. Remember that digital video is essentially just data. A DVD or Blu-Ray disc is just a CD that is capable of holding infinitely more data. A TV is just a monitor that takes data from a DVD, Blu-Ray, game system or the internet and converts it into a picture. Cables and Wi-Fi are the means by which that information is transferred.
Another reason that UHD displays have such high data demands has to do with the number of colors they are capable of displaying. You may have heard of 8-bit, 10-bit or 12-bit color. Those numbers refer to a basic color palette that can be mixed to create a wide gamut of colors. 8-bit color uses 8 base colors to create an overall palette of roughly 16.7-million colors. 12-bit color creates an offering of up to 68.7 billion different colors. All of this is translated into data, which must be encoded onto a disc and uploaded via a cable or streamed via Wi-Fi.
Regardless of how much definition your display (TV) is capable of showing, however, it is only able to show the display size of the data that it receives. So if you use a standard DVD or Blu-Ray player, which are both formatted for 1080p, then you won't get 4K resolution. Cables are the means of transferring information and they are rated for certain data transfer rates. If you use regular HDMI cables with a 4K Blu-Ray player and a UHD TV, you still won't get a 4K picture because standard HDMI cables cannot transfer the data fast enough for full UHD resolution. When your cables and connections are not capable of carrying the data fast enough, you lose the quality and clarity your monitor is capable of delivering.
Why brand matters
While there are certainly lower priced or off-brand cables that can work just fine to deliver an image from your peripheral devices to your monitor, the question is how much data are they capable of delivering? Cables that have slow transfer rates will not be able to transfer data fast enough to deliver the data required to give you the full 4K, 50p, 12-bit color resolution that your monitor is capable of delivering. The problem is that standard HD cables are often labeled 4K cables and sold as such. When purchasing cables for a UHD TV, you should not only work with a reputable retailer, but also a reputable salesperson who can make sure you get the right cables to get the most out of your Ultra High Definition display.