Before we begin answering the difference between solid state and traditional hard disks, let’s take a look at what a solid state drive is. Simply put, an SSD stores information on the semiconductors it’s made up of, rather than the magnetic data disk found in ordinary hard drives. It’s much the same way flash drives work: both use non-volatile memory chips that retain information even when unpowered, but SSDs are much larger in capacity and can replace traditional hard disk drives in laptops and desktop PCs. Some other points on solid state drives vs traditional hard disk drives are elaborated here.They’re also quite a bit more expensive, because overall they’re more efficient than hard disk drives. As the drive has no mechanical parts to move, the information on an SSD is accessed almost instantaneously: there’s no spin-up time, random access time is greatly reduced and data transfer rates are generally more consistent.
Additionally, fragmentation isn’t an issue for SSDs, saving users hours of defragmentation time. They run silently, do not require special cooling and are generally much more hard-wearing (no danger from magnets and shock, for instance, and no mechanical failures) and typically consume up to half as much power as a hard disk drive. There’s a fuller and more detailed comparison here.
Are they worth the money? The performance boost alone, while considerable, may not be enough to justify the extra cost for you, and currently you can get quite a bit more storage space on a hard disk drive for the same price. SSDs are well-suited to laptops, where performance is usually preferred over storage space, although some desktop users successfully combine both a hard disk and an SSD to achieve the best of both worlds of capacity and performance.