What does "4K resolution" mean in video technology?

4K resolution refers to a display resolution of approximately 3840 x 2160 pixels, which is four times the pixel count of 1080p (1920 x 1080 pixels). This higher resolution provides more detail and clarity in images, making it ideal for large screens and high-quality video playback. The term "4K" is derived from the horizontal pixel count, where 4K indicates a resolution with around 4,000 pixels across the width. This significant increase in pixel density allows for a more immersive viewing experience, benefiting various applications such as home entertainment, professional video production, and digital signage.

The other options pertain to different resolutions in the spectrum of video technology. While 1080p (1920 x 1080), 720p (1280 x 720), and QHD or 2K (2560 x 1440) have their respective uses, they do not meet the specifications that define 4K resolution, which distinguishes it by its markedly higher pixel resolution and overall visual fidelity.