SSD (depending on whom you ask) either stands for “Solid State Drive” or “Solid State Disk.” Solid State Drive makes more sense, because the most important characteristic of an SSD is that it in fact has no disk – instead, it stores data on a bank of memory chips.
This approach has several very distinct advantages, especially for laptops. First, with no moving parts, the device has fewer opportunities to break down. (Given that a laptop hard drive requires little moving parts that are so precise they can locate hundreds of billions of microscopic individual bits of data on a tiny disk just a couple of inches across, it’s not surprising that they break down – it’s a miracle they work at all!) In particular, it means that jarring the computer doesn’t risk corrupting data. Second, with no moving parts, their is less energy expended, meaning longer battery life. Lastly, as the computer can pull up the data immediately instead of looking around on a spinning disk, information can be transferred at much higher speeds and computers can start up faster as well.
The down side? At least for now, SSD drives (yes, I realize that means Solid State Drive drive, but I can’t figure out a better way to say it) are significantly more expensive than regular hard drives. Currently, one gigabyte of SSD storage costs about ten times what a gigabyte of hard drive storage costs, which is obviously fairly significant. For some users, however, the advantages outweigh the extra costs, and as the costs continue to drop (as they always do), we will almost certainly see widespread adoption of this technology.