What is ransomware?
A sub-category of malware, whereby malicious software makes its way on to your computer and encrypts large numbers of files. The author of the software then gets in touch to demand payment in order to decrypt the files.
For a long time Mac owners could be smug about ransomware, which was only known to affect PCs. But in March 2016 the first piece of Mac ransomware was spotted.
What's the Refurbished store?
Apple's Refurbished store is great place to pick up bargains.
The products there are pre-owned, but Apple checks them over thoroughly and replaces any worn-out components before putting them on the store. You get a one-year warranty, too. It's the best place to find Macs and iPads that Apple no longer sells new, and always worth a look before buying new - there could be a bargain. The latest generation of products won't be on there, however, so don't expect a bargain on the most recent iPad Air, for instance.
What is a Retina display?
Apple's marketing term for the sharp displays featured on many Mac OS X and most iOS devices. Features a high resolution (comparative to size of display) that packs around 300 pixels into an inch, although the pixel density required to qualify as Retina in Apple's book depends on how far the average user will hold the device from their face - so full-size iPads are rated as Retina at a lower pixel density than iPhones.
The pixel density of Retina displays is considered more than the human eye can pick out individually, so it's fooled (in theory) into thinking it's looking at a real thing, rather than a picture of the thing on a screen.
What is a Retina HD display?
The step beyond Retina.
The only screens currently rated as Retina are those on the iPhone 6 and iPhone 6 Plus. It's not entirely clear what criteria are used to differentiate between Retina and Retina HD screens, but it evidently isn't pixel density, since the iPhone 6 has the same pixel density (326ppi) as its plain-Retina predecessors. (The iPhone 6 Plus, however, has a considerably higher spec: 401ppi.)
It seems that Retina HD is defined as offering wider viewing angles, better contrast, an improved polariser (which lets you view the screen more easily when wearing sunglasses) and a higher resolution - which in this case essentially translates to 'bigger screen'.
Apple user's dictionary of tech jargon: S-U
What is Safari?
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