If you are in the market for a shiny new flat-screen TV or have bought one in recent years, you probably have come across the different resolution labels, specs, and claims by manufacturers.

The most confusing, perhaps, is the difference between Ultra HD and 4K. So, what’s the difference?

Ultra HD, or UHD, refers specifically to the pixel resolution of 3840×2160. This is the actual resolution for most “4K” televisions and projectors and is roughly four times as large as full HD.

4K, strictly speaking, refers to the pixel resolution of 4096×2160 since it really is 4,000 pixels long. This resolution stems from cinema cameras, and is regarded as “real 4K.”

For the average consumer, the difference in quality between UHD and 4K is negligible, and thus manufacturers and retail stores alike have led the way for both resolutions to simply be called 4K interchangeably.

Technically speaking, at 3840×2160, UHD is a little shy of being four thousand pixels long, leading those who really care to denounce it as “fake 4K.”

In addition to TVs, consumers can also expect to see UHD and 4K when looking at 4K video cameras, 4K monitor resolution, or any type of digital 4K content.