Three generations of portable data-storage media. The 5 ¼ inch floppy was introduced about 1975. It started with a capacity of 170 KB but improvements in media pushed the technology to ~1 MB. The next generation of “floppies” was the 3 ½ inch version which was introduced in the early 1980s. These discs had a capacity of 1.4 MB. The 1990s saw the introduction of optically-read media also known as Digital Video Discs (DVDs), as opposed to the earlier magnetically-based media. The capacity of these robust discs increased the storage capacity by three orders of magnitude. Many of the standard DVDs had a capacity of 4-5 GB.
