Link: What do 720p, 1080p, 1440p, 2K, 4K, and other resolutions mean? 

360p is a standard definition (SD) video resolution with 480x360 pixels when the video is in a 4:3 aspect ratio and 640x360 pixels when the video is at a 16:9 aspect ratio. This resolution is commonly used for streaming videos in a bandwidth and data-constrained environment or on smaller mobile screen sizes.

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a 480p video has a resolution of 852×480 pixels. For comparison, a 720p HD video has 720 lines that are each 1,280 pixels wide, meaning that it is more than twice as sharp as a the same video at 480p and can be viewed on a much larger screen.

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What about the numbers? Understanding what screen resolution sizes mean (720p, 1080p, 1440p, 2K, 4K, 8K)

Manufacturers developed a shorthand to explain display resolution sizes when high-definition TVs became the norm. The most common numbers you see today are 1080p resolution (1920 x 1080), 1440p resolution (sometimes also referred to as 2K resolution), 720p resolution (HD), 4K, and 8K. As we have seen, the “p” and the “i” tell you whether it’s a progressive or interlaced scan display. Moreover, this shorthand is sometimes used to describe computer monitors as well, even though, in general, a monitor is capable of a higher definition display than a TV. The number always refers to the number of horizontal lines on the display.

Here’s how the shorthand translates:

• 720p resolution is known as HD or HD Ready resolution and usually means that the display has 1280 x 720 pixels.
• 1080p resolution is also known as FHD or Full HD resolution and typically refers to displays with 1920 x 1080 pixels.
• 1440p resolution is commonly referred to as QHD or Quad HD resolution, and it is typically seen on gaming monitors and high-end smartphones. 1440p (usually 2560 x 1440 pixels) is four times the resolution of 720p HD or HD ready. To make things even more confusing, many premium smartphones feature a so-called 2960 x 1440 Quad HD+ resolution, which still fits into 1440p.
• 4K or 2160p resolution (regularly 3840 x 2160 pixels) is also known as UHD or Ultra HD resolution. It is a huge display resolution, found on premium Smart TVs and computer monitors. 2160p is called 4K because the width is close to 4000 pixels. In other words, it offers four times the number of pixels in a 1080p FHD or Full HD screen.
• 8K or 4320p (generally 7680 x 4320 pixels) offers 16 times more pixels than the standard 1080p FHD or Full HD resolution.