720p vs. 1080p: What You Need to Know About HD Resolutions

Simply put, the more pixels that your TV has on its screen, the more detailed the image quality will be.

Unlike some other numbers found in consumer tech — such as terabytes of memory or gigahertz of processing speed — the designations of 720p and 1080p are easier to visualize, for obvious reasons. More lines of pixels means more visual information on the screen, which is one way to get higher video quality.

Think of your TV screen as a grid. The screen resolution is measured in terms of vertical lines of pixels and horizontal lines of pixels. The FCC defines high definition displays as 720p and above.

Obviously, 1080p TVs have more pixels, although you might be surprised to know that the number refers to the vertical screen resolution, not the horizontal. That is, a 720p TV has 720 vertical lines of resolution, while a 1080p TV has (you guessed it) 1,080 lines.

That lowercase "p" stands for progressive. Originally, video displays used a technique known as interlacing to generate the image. As technology changed and improved, a progressive scan became the industry standard. This allows for a higher perceived image quality.

Since the early days of television, there has been a steady progression in both broadcast and home viewing technology. We've come a long way from the old days of analog signals being sent out over the airwaves. While many modern TVs carry support for antennae, even that signal has been changed to digital.

There's two sides to the equation, of course: the signal that's being sent over your cable or internet connection, and the TV you have at home.

Modern TVs must accommodate changing video feeds, which are now as high as 8K in some cases. As the quest for the best picture quality continues, it's likely that TV resolution will continue to climb, as display technology keeps improving.

At this point, 1080p and 720p have begun to recede into the background. Now, with bigger TVs becoming common (especially those over 50 inches), 4K — also called Ultra HD or UHD — has become the standard with 8K becoming an increasingly common option.

Unlike 1080p and 720p, 4K is actually an approximation of the horizontal resolution number, which is 3,840 pixels. In most cases, the vertical resolution is 2,160.

A 4K TV does have a noticeable difference in image resolution, and in most cases will result in a higher quality video. It's good to keep in mind, however, that 4K is only practical in larger screens, and that not all streaming content can be found in such a resolution.

Display resolution isn't the only thing that will make a difference in your viewing experience. Dynamic range, contrast and color quality all play a role. While there has been a general trend towards cramming as many pixels as possible onto TV screens, there have also been updates in other areas.

1. Screen Size

A larger screen can hold more visual information, and this is why bigger screens tend to boast 4K capability. The downside is that with "standard" video content — say, DVD quality, not even Blu-ray — the image on the screen isn't going to look all that great.

To support such a large screen, you'll need high-resolution source material.

2. Aspect Ratios

These days, much of the video being streamed or watched via cable is in the 16:9 format. This means it's a long-ish, rectangular picture, and most TVs are shaped to suit that shape best.

However, the aspect ratio of various shows and movies is sometimes different, which means that there may be unused space on the top or sides of the screen (usually black bars.)

3. Backlight

Cutting-edge TVs use LED and OLED technology, which allows for a very precise degree of illumination behind the screen. This helps greatly with color quality and contrast (keeping the right balance between the light and dark parts of the image.)

Most Blu-ray disks are encoded in 1080p, and all Blu-ray players support 1080 output. So, if you’re not big on streaming but love watching movies, a 1080p HDTV might still make sense for you.