Wednesday, November 6, 2013

Basic Laptop Knowledge

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Relegated several years ago only to business use, laptop computers now have processing and storage capabilities close to that of desktop computers, and can easily be used for high-tech multimedia purposes (DVD drive, video games, 3D-image processing, etc.). If the price of a laptop computer is still higher than that of a desktop computer because of its mobility, its use is also more varied because of the fact that can be taken virtually anywhere.

However, given its reduced size, most of a laptop computer's pieces are integrated and therefore cannot be changed. This is why users must choose their laptop's characteristics once they are well-informed and have their planned use in mind. On the other hand, the fact that the manufacturer integrates the components allows for reduced risk of hardware incompatibilities (hardware conflicts).

What is a Laptop Computer?

laptop computer (also called notebook computer) is a computer that integrates all the elements that needs to run properly, including a battery power supply, a screen and a keyboard, in a small casing (on average 360 cm x 40 cm x 270 cm). 

Why a Laptop?

The main advantage of a laptop computer versus a desktop computer is its mobility as well as its reduced size. On the other hand, the price is generally higher for slightly less impressive performance and the laptop's hardware configuration is much less adaptable, even though it is possible to connect additional external peripherals thanks to its numerous I/O ports. Therefore, the motivation for buying a laptop computer must above all be a need for mobility or a need to save space. 
Moreover, with the emergence of wireless networks, and WiFi in particular, it is becoming very easy to connect to the Internet in public Hot-Spots or simply in any room of your home as long as it is equipped with a WiFi terminal. 
For advanced multimedia uses (e.g. digital video manipulation, connecting a digital camera or an mp3 player, etc.), the choice should fall on both the computer's performance (both graphic as well as computing power) and on the types and number of I/O ports that are available.

Processor and RAM

The processor represents the computer's brain in that it processes the instructions. Its execution speed depends on its frequency (in MHz), but two processors from different brands that have very different frequencies can perform equally. 
Even though a processor's frequency is still an essential criterion for choosing a laptop computer, today it is preferable to favor the quality of all the components (graphics card, memory, etc.) over only the processor's frequency. 
What is more, the quantity of random access memory (RAM) can have a considerable effect on performance, notably when it comes to multimedia use. In addition to the quantity of memory, it is also important to pay attention to its working frequency, which corresponds to the frequency that most of the peripherals will run on.

Screen

Laptop computers have flat screens. Most of the time they are active matrix screens (generally with the TFTThin Film transistor technology), i.e. each pixel is individually controlled, allowing for improved display fluidity over passive matrix screens, on which pixels are controlled by line and by column. The latest generations of laptops have favored active matrix screens over passive matrix screens. 
The screen is distinguished first of all by its size, which is expressed in inches (an inch equals 2.54 cm) and corresponds to the screen's diagonal length. Unlike screens with cathode ray tubes (CRT screens), the diagonal length of a flat screen corresponds to the effective display area. Moreover, considering the liquid crystal based technologies used in flat screens, the screen quality of a flat screen can be defined by the response time, which is the length of time necessary to turn a pixel from white to black and then back to white. 
The display format is generally 4:3 (i.e. 4 units wide to 3 units high), but there are more exotic laptop display formats that are close to 16:9, such as 15:10, which is adapted to viewing video sequences (e.g. watching DVDs). In general, this type of screen has does not have a whole number diagonal length (e.g. 15.4 inches).

Hard Drive

The hard drive is the area where all the computer's data is stored unlike the RAM, which is a volatile memory that only acts as an information transit area while the computer is running. The most important characteristic of the hard drive is its capacity (expressed in gigabytes), because it determines the amount of data (and, in particular, programs) that a user can store on it. However, it is a good idea to pay particular attention to its performances (in relation notably to its spindle speed), which can hamper the system's overall capacities if they are too weak. 
Using external hard drives (FireWire or USB 2.0) can nevertheless enhance a laptop computer by wiping out the intrinsic limitations of its standard hard drives and extending its storage capacity ad infinitum.

Graphics Card

A laptop computer's graphics card is integrated, i.e. it is a specialized graphics chip (graphic chipset) that is soldered to the motherboard. It is impossible to change it once the laptop has been purchased. Therefore, if the laptop computer will be used for graphics applications (video visualization or manipulation, video games, 3D applications, etc.), it is best to choose a top-of-the-line graphics chipset.

CD/DVD Drive or Burner

More and more laptop computers are making a CD-ROM or a DVD-ROM drive or even a burner into standard features on high-level configurations. When the drive combines several of these functions, it is called a "combo". 
There are different types of CD (with a capacity of about 700 Mb) and DVD (with a capacity of about 4.7 Gb) burners.
  • The term "CD-R" refers to recordable compact disks
  • The term "CD-RW" refers to rewritable compact disks
  • The term "DVD-R" refers to recordable DVDs
  • The term "DVD-RAM" refers to rewritable DVDs Thus, there are two incompatible standards promoted by different manufacturer consortiums:
    • DVD+RW, by Philips, that have performances in terms of recording time that are generally slightly better than the DVD-RW format
    • DVD-RW, which cost slightly less than DVD+RWs

It should be noted that some burners support both of these standards and thus are called "multi-format" burners.

Input/Output Interfaces

Input/output interfaces allow you to extend a laptop computer's functionalities by connecting external peripherals. Laptops generally have PC Card connectors (PCMCIA) that allow you to insert additional peripherals. 
USB ports are available on all recent laptop computers but it is a good idea to verify if they are USB 1.0 ports, which offer a peak throughput of 12 Mbit/s, or USB 2.0 ports, which can have a peak throughput of up to 480 Mbit/s! 
Having IEEE 1394 ports (with the commercial name of FireWire on Apple machines and i.LINK on IBM compatible machines) is a good idea for those users acquiring video from a DV digital video camera. FireWire ports allow throughputs on the order of 800 Mbit/s! 
Some laptops come standard with multi-card readers that can read flash memories in the following different formats: Secure digital (SD Card),Multimedia Card (MMC), Memory stick (MS), SmartMedia (SM), Compact Flash (CF) or xD picture card. This type of reader can be extremely practical for those people who have MP3 players, digital cameras or personal desktop assistants (PDAs) because it facilitates the direct copying of files (e.g. music or digital photos) at a high bandwidth.

Audio and Video Input/Output

Every laptop computer has a screen and internal speakers but in some circumstances it is useful or even necessary to connect it to higher performance stereo or video systems (e.g. for a presentation or for a DVD projection). 
Laptop computers come standard with a VGA connector, which allows you to connect them to an external monitor or a video projector. Sometimes laptops come equipped with a video output (called a TV output), i.e. a S-Video connector that allows you to connect the computer directly to a television. 
With regard to audio I/O, all laptop computers come with standard headphone and microphone jacks as well as stereo speakers of varying quality. Having a S/PDIF output (digital audio output) can allow users to connect their laptop to a sound system that supports Dolby Digital 5.1 (e.g. for Home Cinema use).

Pointing Device / Keyboard

Laptop computers come standard with an integrated keyboard and pointing device. The pointing device is generally a touchpad, i.e. a flat touch-sensitive surface that allows you to move the cursor like a mouse. Some laptops come equipped with a trackpoint, i.e. a little touch-sensitive eraser-like tip (generally red) located in the middle of the keyboard that allows users to move the cursor with their fingers. 
The keyboard and pointing device should be chosen according to their ergonomics. They should be tried out in order to determine if they are comfortable to use. 
It should be noted that nothing prevents users from connecting a traditional mouse to a laptop computer for more comfort.

Mobility and Network Connectivity

In the communications world that we live in today, it is impossible to imagine a laptop computer without network functionalities. The terms nomadism andmobility are used to refer to individuals' capacity to have access to their information over the Internet, no matter where they are. 
Most laptop computers come standard equipped with a 56K V90 modem that allows them to connect to the Internet over the telephone network (STN,switched telephone network). 
The "10/100 Mbit Fast Ethernet" connector can be used to connect a laptop to a local area network (LAN) or to connect it to network equipment such as an ADSL modem, a router, a switch or even directly to another computer with acrossover network cable. 
With the emergence of wireless networks and the increased number of public and private wireless network access points (called hot spots), the concept of nomadism is taking on a whole new meaning. Thus, some laptop computers now come standard with built-in or card WiFi adapters. WiFi technology allows computers equipped with specialized adapters (WiFi cards) to connect with each other over a range of several dozen or even hundreds of meters and possibly even to connect to the Internet thanks to a wireless router (WiFi terminal). There are several WiFi standards that use different transmission channels:
  • WiFi 802.11a for a throughput of 54 Mb/s (30 Mb/s of real throughput)
  • WiFi 802.11b for a throughput of 11 Mb/s (6 Mb/s of real throughput) with a range of up to 300 meters in an open environment
  • WiFi 802.11g for a throughput of 54 Mb/s (30 Mb/s of real throughput) on a frequency band of 2.4 GHz.



Some laptops are equipped with Bluetooth technology, which is another wireless network technology. However, it is used primarily for wireless personal area network (WPAN), i.e. it is intended for small wireless devices such as mobile phones, PDAs, etc. 
IrDa (infrared) technology allows users to connect small devices wirelessly to each other but, unlike BlueTooth technology, has distance limitations (several dozen centimetres facing each other) and reduced throughput.

Technical Characteristics

When you buy a laptop computers, in addition to choosing specific hardware elements you should carefully weigh the following characteristics:
  • weight: a laptop computer is made to be transported, so it is important to choose the lightest one possible. Nevertheless, watch out for laptops that are light and have many external peripherals (CD-ROM/DVD-ROM drive, mouse, power supply, hubs, etc.)
  • autonomy: Computer autonomy depends on how much energy a computer's components use as well as the battery's characteristics
    • NiCad (Nickel / Cadmium): a rechargeable battery that is now obsolete because it suffered from the memory effect, i.e. a progressive decrease in the maximum charge when it is recharged when it is not completely "dead"
    • NiMH (Nickel / Hybrid Metal): a rechargeable battery that works better than nickel-cadmium batteries
    • Li-Ion (Lithium / Ion): a rechargeable battery used in most laptop computers. Li-Ion batteries perform well and are reasonably priced. Moreover, Li-Ion batteries do not suffer from the memory effect, which means that it is not necessary to run the battery dry before recharging it.
    • Li-Polymer (Lithium / Polymer): a rechargeable battery that is equivalent to Li-Ion batteries in terms of performance but is much lighter because the battery electrolytes and microporous separator in Li-Ion batteries are replaced by a solid polymer that is much lighter. On the other hand, Li-Polymer batteries take longer to charge and their longevity is shorter

Generally, computer autonomy is expressed in the amount of time that a computer can remain in sleep mode and in use.
  • Operating Temperature: Running certain parts of a laptop computer (particularly the processor) causes the temperature of the computer to increase and sometimes become bothersome (especially when the keyboard becomes too hot).

Overheating can become a real danger that can worsen when the laptop is running with the screen down because this can prevent proper thermal dissipation. 
  • noise: In order to dissipate the heat caused by the running of different parts of the laptop (especially the processor), laptop computers are sometimes equipped with heat evacuation devices, such as fans, that can create loud, bothersome noises. This is also true for that motors that run the hard drives and CD/DVD drives/burners. Therefore, it is a good idea for buyers to enquire about the level of noise the computer makes when it runs.


Docking Station

Some laptops come with a docking station. This is the device that the laptop computer fits into in order to easily connect it with a keyboard, mouse, screen, etc.

Warranty

Buying a laptop computer is a big investment. Therefore it is necessary to protect yourself against the risks associated with computer failure by signing up for a warranty. The warranty is even more important for laptop computers because it is not possible to change parts (graphics card, sound card, etc.) like you can on desktop computers. Most offers automatically include at least one year but it might be a good idea to take a several year warranty extension in order to cover the maximum number of risks. 

Make sure you get information about the type of damages that are covered by the warranty. Batteries in particular are rarely covered.


Software Package

Laptop computers are almost systematically equipped with an operating system when you purchase them but some offers also include a whole package of useful software such as office tools, an encyclopaedia or even antivirus software. It is a good idea to keep this in mind when you are buying a laptop.

Protective Cover

If you are going to travel with your computer, it is necessary to have a computer bag in order to protect it when transporting it with all its accessories. 

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