History of laptop technology

A laptop computer, or simply laptop (also notebook computer or notebook), is a small mobile computer, which usually weighs 2-18 pounds (1-6 kilograms), depending on size, materials, and other factors.many term of laptop like as : Sony vaio,trevelmate acer, lifebook fujitsu,notebook thosiba,hewlettpackard compac and IBM
Laptops usually run on a single main battery or from an external AC/DC adapter which can charge the battery while also supplying power to the computer itself. Many computers also have a 3 volt cell to run the clock and other processes in the event of a power failure.
As personal computers, laptops are capable of the same tasks as a desktop computer, although they are typically less powerful for the same price. They contain components that are similar to their desktop counterparts and perform the same functions, but are miniaturized and optimized for mobile use and efficient power consumption. Laptops usually have liquid crystal displays and most of them use different memory modules for their random access memory (RAM), for instance, SO-DIMM in lieu of the larger DIMMs. In addition to a built-in keyboard, they may utilize a touchpad (also known as a trackpad) or a pointing stick for input, though an external keyboard or mouse can usually be attached.
Terms sometimes used for subtypes of laptop computers include:
UMPCs
These Ultra-Mobile PCs are mobile computers with a size comparable to PDAs - they are extremely portable. Because of their small size, they incorporate a 20 cm (7 inch) or smaller touch-screen for the user to interact with it (as with a virtual keyboard), though some (such as the OQO Model 02) are designed with a miniature physical keyboard (a thumbboard) and mouse interface. They house lower performing, power-saving components (in comparison to larger laptops). Examples of UMPCs are the OQO Model 02 and the Sony VAIO UX Micro PC.
Ultraportables
Laptops with screens typically 12 inches or less diagonally and a weight of less than 1.7kg. Their keyboards are usually not full-size. Their primary audience is usually business travelers, who need small, light laptops. Ultraportables are often very expensive, have extended battery life, house power-saving CPUs and almost always have integrated graphics.
A Sony VAIO FJ76 Notebook
Thin-and-lights
Laptops usually weighing in between 1.8kg and 2.8kg with a screen size of between 12 and 14 inches diagonally. Examples of this variety: the Sony VAIO CR , HP Pavilion DV2000 and Apple MacBook .
Desktop replacement computers
Powerful laptops meant to be mainly used in a fixed location and infrequently carried out due to their weight and size; the latter provides more space for powerful components and a big screen, usually measuring 15-20 inches. Desktop replacements tend to have limited battery life, rarely exceeding three hours, because the hardware is not optimized for efficient power usage. Sometimes called a luggable laptop. An example of a desktop replacement computers are gaming notebooks, which are designed to handle 3D graphic-intensive processing for gamers. These notebooks possess similar features as desktop notebook computers.

[edit] Related devices
Laptops can be understood as a particular point on the continuum of more or less portable computing devices: the point at which the device is large enough to use substantially the same software as a desktop machine, but small enough to support Mobile computing. Other points on the continuum include:
Transportables, also called portable computers
Computers which can easily be moved from place to place, but cannot be used while in transit, usually because they require AC power. The most famous example is the Osborne 1. A transportable, like a laptop, can run desktop software; but it does not support mobile computing.
Tablets
Computers shaped like slates or (paper) notebooks, with touchscreen interfaces. As of 2007, the most common subcategory is the Tablet PC, which is essentially a laptop with a touchscreen. Some tablets have no keyboard; others, called "convertibles", have a keyboard which can be folded behind the screen. Tablets may have limited functionality in certain applications that require an actual physical keyboard for typing, but are otherwise capable of carrying out most tasks that an ordinary laptop would be able to perform.
Internet tablets
Internet appliances in tablet form. An internet tablet supports mobile computing, Internet tablets usually use linux and theyre able to run some applications but they cant replace a computer, Internet tablet feature a MP3,Video, Internet Browser, Chat, and picture viewer
Personal digital assistants (PDAs)
Small computers, usually pocket-sized, usually with limited functionality. A PDA supports mobile computing, but almost never runs any desktop software.
Handheld computers
A high-end PDA or small tablet.
Smartphone
A handheld or PDA with an integrated cellphone.
As will be clear, these categories are blurry at times. For example, the OQO UPC is a PDA-sized Tablet PC; the Apple eMate had the clamshell form factor of a laptop, but ran PDA software. The HP Omnibook line of laptops included some devices small enough to be called handheld computers. The hardware of the Nokia 770 Internet tablet is essentially the same as that of a PDA such as the Zaurus 6000; the only reason it's not called a PDA is that it doesn't have PIM software. On the other hand, both the 770 and the Zaurus can run some desktop Linux software, usually with modifications.