To turn on this feature, go to Settings > Personalization > Lockscreen. Note This feature might not be available to all users because it will roll out gradually.
The 21.5in iMac with 4K Retina display might not be as big as the 27in iMac, and it might not have as many pixels as that model, but it finally brings the Retina display on the iMac to around the ...
Is the new 21-inch 4K Retina iMac from Apple worth buying? Find out what the critics are saying about it before you buy one The latest version of Apple’s 21-inch iMac sports a 4K Retina screen, and ...
AppleInsider: Review: Apple's 21.5-inch iMac with 4K Retina display is great, but skip the slow HDD model
Apple's marketing team didn't need to dig deep to dream up a campaign for the new 21.5‑inch iMac with Retina 4K display — its best feature is in the name. The stellar ultra high-resolution screen ...
Review: Apple's 21.5-inch iMac with 4K Retina display is great, but skip the slow HDD model
Macworld: iMac with 4K Retina display review: A high-resolution desktop Mac for the masses
iMac with 4K Retina display review: A high-resolution desktop Mac for the masses
The retina is the layer inside your eye that detects light and converts it into signals your brain can use. It’s critical for your vision.
Retina of the Eye: What It Is, Function & Anatomy - Cleveland Clinic
The retina (from Latin rete 'net'; pl. retinae or retinas) is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs.