A 4K screen has a resolution of 3840 x 2160 pixels, which is also called Ultra High Definition (UHD). This is four times as many pixels as Full HD 1080p, which has a resolution of 1920 x 1080.

That's where it gets sticky. We're talking about a similar jump in resolution as the one from SD (480 lines high) to HD (1080 lines high). And 4K screens are noticeably sharper than 1080p screens.

You’ll need compatible equipment such as a high-resolution audio player, a digital-to-analog converter (DAC), and high-quality headphones or speakers to listen to hi-res audio.

After updating, they'll have the option to send images to friends and family in "HD quality," which equates to 3024 x 4032 resolution. The rollout of the feature was announced by Meta CEO Mark ...