A laptop, also called a notebook, is a small mobile computer. Depending on the size, material used for manufacturing it and other factors, its weight ranges from 1 to 8 kilograms (i.e. 2 to 18 pounds).
The source of power is usually a single main battery, or an external AC/DC adapter is used. Apart from supplying power to the laptop, it also charges the battery. To avoid havoc in case of power failure, a 3 Volt cell is provided to run the clock and other vital system processes.
Though laptops are equally capable and powerful as desktop computers, they are much more expensive than similar capability and configuration desktop computer. Size is the unique property of a laptop. The components used in both, laptops and desktops are the same in terms of the functions they perform, but the components in laptops are miniaturized and made to support efficient power consumption.
LCD (Liquid Crystal Display) is usually the technology used for the display screen. They have a built-in keyboard and a touchpad as input devices. Provision is also made for connection of external mouse, and even keyboard.
Apart from the advantages like compactness and mobility, a set of disadvantages has also been associated with laptops.
A huge amount of discrepancy is observed when it comes to standardization issues of laptops. There exist worldwide standards for form factors of the peripherals and add-in PC cards used in a desktop computer. But no such standards are as yet enforced for form factors of laptop internals. Electric voltage, motherboard layouts, internal adapters used in connecting the hard disk, optical drive, LCD cable, keyboard and floppy drive to the main board, all still face issues with standardization. These hits hard on the poor user who is uneducated in this relevant field. Apart from them, a bit of difficulty may also be faced by the repair technicians. Familiarization of different parts and hardware that perform the same function is important.
As an outcome of the improper, or all most no standardization, the laptops suffer compatibility problems too. Most of the times, it is not possible to use one manufacturers components in the laptop produced by another manufacturer. The reasons behind this can be assurance of product stability, prolong product lifetime, and to avoid dubious warranty issues. Some manufacturers provide the laptops with a set of ports to let the user connect the hardware that he wants to use.
Upgradation of a laptop is another issue. Due to both technical and economic reasons, it is limited. Due to the proprietary designs of the laptops by each manufacture, it is difficult to upgrade them and most of the times even repairing is a costly affair. The standard peripherals, like audio, video, USB, 1394, Wi Fi, Bluetooth, are integrated in the motherboard. Upgrading these thus requires either of external ports, card slots or wireless peripherals. As far as the memory units and batteries are concerned, they can generally be upgraded according to the users needs.
Performance is another issue. RAM is shared between program memory and graphic adapters in laptops. Because of which performance of the laptop is affected. The major concern of the designer is compactness and energy efficiency against high performance. Generally, for the home requirement, laptops prove out to be good options for fast achievement of required performance. With new technology like dual core processors and perpendicular recording, laptops performance is already showing a progressive graph when compared to the desktops.
Laptops can also pose health hazards. Temperature generated by laptop can affect sterility in men. Also, laptop keyboard can lead to RSI (Repetitive Strain Injury). Thus it is advised to place the laptop on a table or desk when working.