Here’s one that makes me think, “Which is it?”

English: Compact Disc Nederlands: Compact Disc

English: Compact Disc Nederlands: Compact Disc (Photo credit: Wikipedia)

Actually, it’s an easy one. Before the age of computers there were only discs, and a disc could be any flat circular thing, a vinyl record or pretty much anything which had roughly the same shape. There are disc galaxies in space and disc brakes on cars. Getting more modern, we have CDs (Compact Discs), DVDs (Digital Versatile Discs), both of which are pressed, optically-read discs.

A hard-disk, and any other kind of disk you can put in your computer to store or ‘burn’ your own stuff on, is different and stores data on a magnetic layer. This means that many of them can be used more than once, as the magnetic ‘memory’ can be erased to make room for new stuff. These disks should also be stored more carefully. For example, they should not be kept next to magnets, and as every speaker has a magnet inside it’s not smart to use your woofers and tweeters as ‘bookends’ for your storage disk collection.’