Hard Drives For Laptops

Long before the first laptop arrived on the market, the idea behind it was ready. Back in 1968, a "personal, portable information manipulator" was imagined by Alan Kay at Xerox PARC, and this idea was described accurately in his 1972 paper, as the "Dynabook."
A few years later, back in the early days of mobile computing, any so-called "portable computer" had about 20 pounds, and no hard drive, since storage was usually provided by dual 5¼" single-density floppy drives. That's clear - back in the 1870s, it was too early for laptop hard drives, but don't worry...we're getting there right away!
In 1982, when the first clamshell design was introduced in a portable computer, the hard drive still remained outside of it, but since 1983, the term "laptop" started being used, and soon hard drives were also introduced, alongside with CD-ROM drives).
Basically, now we have two generations of hard drives present in laptops - the classic hard drive, and the SSD. A few years ago, I remember that some hybrid drives were also introduced in some higher end laptops, aiming to help save power and increase boot times, by using a flash memory/classic HDD couple, but since it didn't actually go mainstream, let's talk about what we can currently call "laptop hard drives," shall we?
Currently, most laptops have 2.5-inch or 11.8-inch hard drives, while desktop ones are 3.5-inch models. Their rotational speed is, usually, 5400 or 7200rpm, and they have at least 8MB buffer memory, and capacities of up to 500GB.
Some producers into the laptop drives market aren't popular in the desktop drives one, such as Toshiba. It is worth mentioning the fact that, in the last two years, laptop hard drives prices went down a lot, allowing easy upgrades/replacements(easy on the budget, you know...).
At last, we have the solid state drives, also known as SSDs, with capacities starting at 4GB for some netbooks, and up to 128GB. Obviously, this solution is more expensive, but we could see the SSD completely replacing the classic HDD in a few years.