Hard-disk drives are best suited to users who need vast amounts of storage and aren't as concerned about achieving peak system performance. If you're an everyday PC user who sticks mostly to email, Web browsing, and basic document editing, a standard hard drive should suit you fine. Just don't tinker around with someone else's SSD-powered PC, because once you've gotten a taste of a solid-state drive's blazing read/write speeds, it's hard to go back to even the speediest of traditional hard drives.
On many levels, solid-state drives are similar to hard drives. They usually connect to a system by way of the SATA interface (though PCI Express-based drives are also available for ultrahigh-performance applications), and they store files just as any other drive does. SSDs, however, eschew the magnetic platters and read/write heads of hard-disk drives in favor of nonvolatile NAND flash memory, so no mechanical parts or magnetic bits are involved.
By ditching the relative slothfulness of moving parts, solid-state drives deliver much better performance. They're the fastest storage option available. And not only can SSDs read and write data much faster than hard drives with most workloads, but they can also access the data much more quickly as well.
Whereas the fastest hard drives can read and write data at about 200MB per second and access data in a few milliseconds, the fastest solid-state drives can achieve 550-MBps (or higher) transfers that essentially saturate the SATA interface, and their typical access times are a fraction of a single millisecond. In a nutshell, SSDs make for a much snappier, much more responsive system, with lightning-fast boot times, application launch times, and file-transfer speeds.
Another huge SSD advantage is durability. Because they have no moving parts, solid-state drives aren't susceptible to damage or degraded performance from vibrations or movement. Drop a system or laptop containing a traditional hard-disk drive, and you have a very real chance of corrupting your data. But a solid-state drive won't--can't--skip a beat.
Solid-state drives aren't without disadvantages, though. For one, SSDs are much more expensive than hard drives in terms of cost per gigabyte. Good, consumer-class solid-state drives run about $0.70 to $1.00 per gigabyte, whereas hard drives cost only a few cents per gigabyte. Solid-state drives don't offer anything near the capacity of hard drives, either: The most popular SSDs have capacities of about 120GB to 256GB, with 512GB to 1TB models reserved only for those with gargantuan budgets.