Subnotebooks are usually smaller and lighter than standard laptops, weighing between 0.8 and 2 kg (2-5 lb), Since the introduction of netbooks and ultrabooks, the line between subnotebooks and either category has blurred.
Netbooks are a more basic and cheap type of subnotebook, and while some ultrabooks have a screen size too large to qualify as subnotebooks, certain ultrabooks fit in the subnotebook category.
Some CPUs, such as the 1990 Intel i386SL, were designed to use minimum power to increase battery life of portable computers and were supported by dynamic power management features such as Intel Speed Step and AMD Power Now! Displays reached 640x480 (VGA) resolution by 1988 (Compaq SLT/286), and color screens started becoming a common upgrade in 1991, with increases in resolution and screen size occurring frequently until the introduction of 17" screen laptops in 2003.
Hard drives started to be used in portables, encouraged by the introduction of 3.5" drives in the late 1980s, and became common in laptops starting with the introduction of 2.5" and smaller drives around 1990; capacities have typically lagged behind physically larger desktop drives.
Hardware specifications, such as the processor speed and memory capacity, significantly vary between different types, makes, models and price points.
Design elements, form factor and construction can also vary significantly between models depending on intended use.
It can be easily folded to conserve space while traveling.
Examples of specialized models of laptops include rugged notebooks for use in construction or military applications, as well as low production cost laptops such as those from the One Laptop per Child (OLPC) organization, which incorporate features like solar charging and semi-flexible components not found on most laptop computers.
Portable computers, which later developed into modern laptops, were originally considered to be a small niche market, mostly for specialized field applications, such as in the military, for accountants, or for traveling sales representatives.
As portable computers evolved into the modern laptop, they became widely used for a variety of purposes.
The terms laptop and notebook are used interchangeably to describe a portable computer in English, although in some parts of the world one or the other may be preferred.