Monday, May 7, 2012

Advantages and Disadvantages of Using Computers


Society has reaped many benefits from using computers. A user is anyone who communicates with a computer or utilizes the information it generates. Both business and home users can make well-informed decisions because they have instant access to information from anywhere in the world. Students, another type of user, have more tools to assist them in the learning process.


Advantages of Using Computers 

Benefits from using computers are possible because computers have the advantages of speed, reliability, consistency, storage, and communications.

  • Speed: When data, instructions, and information flow along electronic circuits in a computer, they travel at incredibly fast speeds. Many computers process billions or trillions of operations in a single second. Processing involves computing (e.g., adding, subtracting), sorting (e.g., alpha betizing), organizing, displaying images, recording audio, playing music, and showing a movie or video.
  • Reliability: The electronic components in modern computers are dependable and reliable because they rarely break or fail.
  • Consistency: Given the same input and processes, a computer will produce the same results — consistently. A computing phrase — known as garbage in, garbage out — points out that the accuracy of a computer’s output depends on the accuracy of the input. For example, if you do not use the flash on a digital camera when indoors, the resulting pictures that are displayed on the computer screen may be unusable because they are too dark.
  • Storage: A computer can transfer data quickly from storage to memory, process it, and then store it again for future use. Many computers store enormous amounts of data and make this data available for processing anytime it is needed.
  • Communications: Most computers today can communicate with other computers, often wirelessly. Computers with this capability can share any of the four infor ma tion processing cycle operations — input, process, output, and storage — with another computer or a user.



Disadvantages of Using Computers

Some disadvantages of computers relate to health risks, the violation of privacy, public
safety, the impact on the labor force, and the impact on the environment.

  • • Health Risks: Prolonged or improper computer use can lead to injuries or disorders of the hands, wrists, elbows, eyes, neck, and back. Computer users can protect themselves from these health risks through proper workplace design, good posture while at the computer, and appropriately spaced work breaks. Two behavioral health risks are computer addiction and technology overload. Computer addiction occurs when someone becomes obsessed with using a computer. Individuals suffering from technology overload feel distressed when deprived of computers and mobile devices. Once recognized, both computer addiction and technology overload are treatable disorders. Read Ethics & Issues 1-1 for a related discussion.
  • Violation of Privacy: Nearly every life event is stored in a computer somewhere . . . in medical records, credit reports, tax records, etc. In many instances, where personal and confidential records were not protected properly, individuals have found their privacy violated and identities stolen.
  • Public Safety: Adults, teens, and children around the world are using computers to share publicly their photos, videos, journals, music, and other personal information. Some of these unsuspecting, innocent computer users have fallen victim to crimes committed by dangerous strangers. Protect yourself and your dependents from these criminals by being cautious in e-mail messages and on Web sites. For example, do not share information that would allow others to identify or locate you and do not disclose identification numbers, passwords, or other personal security details.
  • Impact on Labor Force: Although computers have improved productivity in many ways and created an entire industry with hundreds of thousands of new jobs, the skills of millions of employees have been replaced by computers. Thus, it is crucial that workers keep their education up-to-date. A separate impact on the labor force is that some com panies are outsourcing jobs to foreign countries instead of keeping their homeland labor force employed.
  • Impact on Environment: Computer manufacturing processes and computer waste are depleting natural resources and polluting the environment. When computers are discarded in landfills, they can release toxic materials and potentially dangerous levels of lead, mercury, and flame retardants. Green computing involves reducing the electricity consumed and environmental waste generated when using a computer. Strategies that support green computing include recycling, regulating manufacturing processes, extending the life of computers, and immediately donating or properly disposing of replaced computers. When you purchase a new computer, some retailers offer to dispose of your old computer properly.


Thursday, May 3, 2012

The Components of a Computer



A computer contains many electric, electronic, and mechanical components known as hardware. These components include input devices, output devices, a system unit, storage devices, and communications devices.

1. Input Devices

An input device is any hardware component that allows you to enter data and instructions
into a computer. Five widely used input devices are the keyboard, mouse, microphone, scanner, and Web cam.


A computer keyboard contains keys you press to enter data into the computer. For security
purposes, some keyboards include a fingerprint reader, which allows you to work with the computer only if your fingerprint is recognized.


A mouse is a small handheld device. With the mouse, you control movement of a small symbol on the screen, called the pointer, and you make selections from the screen.
A microphone allows you to speak into the computer. A scanner converts printed material
(such as text and pictures) into a form the computer can use.


A Web cam is a digital video camera that allows you to create movies or take pictures
and store them on the computer instead of on tape or film.

2. Output Devices

An output device is any hardware component that conveys information to one or more people. Three commonly used output devices are a printer, a monitor, and speakers.


A printer produces text and graphics on a physical medium such as paper. A monitor
displays text, graphics, and videos on a screen. Speakers allow you to hear music, voice, and other audio (sounds).

3. System Unit

The system unit is a case that contains the electronic components of the computer
that are used to process data. The circuitry of the system unit usually is part
of or is connected to a circuit board called the motherboard.


Two main components on the motherboard are the processor and memory. The processor,
also called a CPU (central processing unit), is the electronic component that interprets and carries out the basic instructions that operate the computer. Memory consists of electronic components that store instructions waiting to be executed and data needed by those instructions.


Although some forms of memory are permanent, most memory keeps data and
instructions temporarily, which means its contents are erased when the computer is
shut off.

4. Storage Devices

Storage holds data, instructions, and information for future use. For example, computers
can store hundreds or millions of customer names and addresses. Storage holds these
items permanently.


A computer keeps data, instructions, and information on storage media . Examples of storage media are USB flash drives, hard disks, optical discs, and memory cards. A storage device records (writes) and/or retrieves (reads) items to and from
storage media. Drives and readers/writers, which are types of storage devices, accept a specific kind of storage media. For example, a DVD drive (storage device) accepts a DVD (storage media). Storage devices often function as a source of input because they
transfer items from storage to memory.


A USB flash drive is a portable storage device that is small and lightweight enough to
be transported on a keychain or in a pocket. The average USB flash drive can hold about 4 billion characters. You plug a USB flash drive in a special, easily accessible opening
on the computer.


A hard disk provides much greater storage capacity than a USB flash drive. The average
hard disk can hold more than 320 billion characters. Hard disks are enclosed in an airtight, sealed case. Although some are portable, most are housed inside the system unit.


Portable hard disks are either external or removable. An external hard disk is a separate, freestanding unit, whereas you insert and remove a removable hard disk from the computer or a device connected to the computer.


An optical disc is a flat, round, portable metal disc with a plastic coating. CDs, DVDs,
and Blu-ray Discs are three types of optical discs. A CD can hold from 650 mil lion to
1 billion characters. Some DVDs can store two full-length movies or 17 billion characters. Blu-ray Discs can store about 46 hours of standard video, or 100 billion
characters.


Some mobile devices, such as digital cameras, use memory cards as the storage media. You can use a card reader/writer to transfer the stored items, such as digital photos, from
the memory card to a computer or printer.

5. Communications Devices

A communications device is a hardware component that enables a computer to send
(transmit) and receive data, instructions, and information to and from one or more computers or mobile devices. A widely used communications device is a modem.


Communications occur over cables, telephone lines, cellular radio networks, satellites, and other transmission media. Some transmission media, such as satellites and cellular radio networks, are wireless, which means they have no physical lines or wires.


Tuesday, May 1, 2012

Terms of Computer IT

10-Gigabit Ethernet:Ethernet standard that supports transfer rates up to 100 Gbps.
100-Gigabits Ethernet:Ethernet standard that supports transfer rates up to 100 Gbps.
128-bit encryption:Higher-level web browser encryption protection level.
1024-bit encryption:Higher-level web browser encryption protection level.
1NF:First Normal Form
1G:Abbreviation for first generation, used in reference to cellular transmission standards, used to transmit analog data.
2G:Abbreviation for second generation, used in reference to cellular transmission standards, that transmit digital data at speed from 9.6 Kbps to 19.2 Kbps.
2G:Abbreviation for third generation, used in reference to cellular transmission standards, that transmit digital data at speed from 144 Kbps to 2.4 Mbps.

What Is a Computer?

A Computer is an electronic device, operating under the control of instructions stored in its own memory, that can accept data, process the data according to specified rules, produce results, and the results for future use.


Computers process data information. Data is a collection of unprocessed items, which can include text, numbers, images, audio, and video. Information conveys meaning and useful to people.

Information Processing Cycle

Computer process data (input) into information (output). Computers carry out processes using instructions, which are the steps that tell the computer how to perform a particular task. A collection of related instructions organized for a common purpose is referred to as software.

A computer often holds data, information, and instructions in storage for future use. Some people refer to the series of input, process, output, and storage activities as the information processing cycle.

Most computer today communicate with other computers. As a result, communications also has become an essential element of the information processing cycle.

The Components of a Computer

A computer contain many electric, electronic, and mechanical components known as hardware. There are 5 main components of computer.
  1. Input devices
  2. Output devices
  3. System unit
  4. Storage devices
  5. Communications devices