What is Laptop?
A laptop computer (also known as notebook computer) is a small mobile personal computer, usually weighing around from 1 to 3 kilograms (2 to 7 pounds). Notebooks smaller than an A4 sheet of paper and weighing around 1 kg are termed subnotebooks and those weighing around 5 kg a desknote (desktop/notebook). Predecessors of the laptop include the Osborne 1 and the Macintosh Portable, each of which weighed 20-30 pounds (due in part to being powered by hefty lead acid batteries) but nonetheless offered novel mobile computing platforms. Laptops are generally popular among students, travellers, and telecommuters.
Laptops are capable of many of the same tasks that desktop computers perform, although they are typically less powerful. Laptops contain components that are similar to those in their desktop counterparts and perform the same functions but are miniaturized and optimized for mobile use and efficient power consumption. Laptops usually have LCD displays and smaller SODIMM (Small Outline DIMM) chips for their RAM. In addition to a built-in keyboard, they may utilize a touchpad or a pointing stick for input, though an external mouse or keyboard can usually be attached.
Current models use LiIon batteries, which have largely replaced the older NiMH technology. Typical battery life for most laptops is two to five hours with light-duty use, but may drop to as little as one hour with intensive use. Batteries gradually degrade over time and eventually need to be replaced, commonly after two to five years.
Most modern laptops use an active matrix display, with screen sizes 14 inches or larger, and have PCMCIA expansion bays for expansion cards. Internal hard disks are smaller---2.5" compared to the standard desktop 3.5 inch drive---and have lower performance. Display adapters and sound cards are integrated. Modern laptops can often handle sophisticated games but tend to be limited by their fixed screen resolution and display adapter type. Docking stations are used for expanding connectors and quickly connecting many components to the laptop.
Laptops generally cost around twice as much as a desktop machine of similar specification. Upgradability is severely limited: typically only the RAM and hard drive can be changed. Because nearly all functions are integrated into the proprietary-design mainboard to save space and power, laptops are seldom user-servicable. Unless the unit is under warranty, the cost of repairing even a minor fault is close to the cost of simply buying a completely new laptop.
How Laptops Woks?
In a way, the skyrocketing popularity of laptop computers is ironic. They're completely portable, and they use less power and make less noise than desktop models. But, they're often a little slower and have less graphics and sound processing power, although these differences can be too small for most users to notice.
Laptops are also more expensive than desktops. The price gap is closing, though -- laptop prices are falling faster than desktop prices, and laptop PCs actually outsold desktop models for the first time in May of 2005 [Source: Windows IT Pro].
How can all the equipment found in a desktop tower fit into such a small package? And how can laptops be efficient enough to run on battery power alone? In this article, you'll discover the answers to these and other questions about laptops.
Overall, laptop and desktop computers are very similar. They have the same basic hardware, software and operating systems. The primary difference is how their components fit together.
A desktop computer includes a motherboard, video card, hard drive and other components in a large case. The monitor, keyboard, and other peripherals connect wirelessly or with cables. Whether the case sits vertically or horizontally, it has lots of space for add-in cards, cables and air circulation.
A laptop, however, is much smaller and lighter than even the most compact PC tower. Its screen is an integrated part of the unit, as is its keyboard. Instead of a spacious case with lots of room for air circulation, a laptop uses a small, flat design in which all the pieces fit together snugly.
Because of this fundamental design difference and because of a laptop's inherent portability, components have to:
* Fit into a compact space
* Conserve power
* Produce less heat than desktop components
Often, these differences make the components more expensive, which can contribute to higher laptop prices. In the following sections, we'll examine how laptops handle these differences.
