Personal Computer Basics

Personal Computer

A personal computer is a stand-alone computer that is equipped with a central processing unit (CPU), one or more disk drives, random access memory (RAM), a monitor, a keyboard, and a mouse.

It comes in a variety of shapes and sizes.

A personal computer is a device that allows you to do a lot of work in a very short amount of time. It allows you to communicate with businesses, friends, family and strangers around the world. It helps you organize all of your information from your personal address book to your checkbook. 

Types of PCs

There are two broad categories of PCs: stay at home and portable.

Home computers come in two basic models, desktop and tower.

The desktop model sits horizontally on your desk while the tower model sits vertically. The orientation of the system box is the only difference in the two computers. Due to their size, they are not frequently moved.

Portable computers such as laptops and notebooks are much smaller and are easily transported. They are lightweight and can sit comfortably in your lap. They run on batteries and connect to household electricity.

Computer Hardware

Hardware is a term for the physical components that are included when you purchase a PC. They include the system box, monitor, keyboard and mouse.

You can purchase additional hardware items such as modems, scanners CD-ROM drives, DVD drives, video cameras and whatever else the computer gurus invent.

By itself, hardware is not capable of doing anything. Look at your stereo. It sits there looking nice, without emitting sounds until the hardware pieces are given the sounds to play.

Your computer needs something to make it work. That something is software. 

Computer Software

Software tells the hardware how to work, what to do, and when to do it. It includes the basic operating system, utility, or application programs, all expressed in a language your hardware understands.

There is software to tell your computer to do just about any task. Think about when you first balanced your checkbook. Either someone showed you how to do it or you followed the instructions on the back of your statement.

Those instructions "programmed" you on how to do the task at hand: balancing your checkbook. Those instructions were your "software" and you were the "hardware" that did the work. 

Applications

Software applications are programs that a computer uses so that the machine completes predetermined tasks.

Each application performs a specific kind of work, such as, word processing, desktop publishing and accounting, personal finance, etc.

A utility program is an after-market application that does housekeeping operations to assist you in maintaining and improving your computer's performance.

Operating Systems

An operating system is the master control program for the computer. It is the stored information that your computer needs to operate.

Without an operating system all of the hardware would just sit there and collect dust. 

Central Processing Unit (CPU)

It is the computer chip that does all of the processing for the computer.

Inside this tiny chip are millions of transistors (electrical switches) that are connected so they can carry out mathematical calculations. Everything a computer does is essentially a mathematical calculation.

CPU Speed

We measure the central processing unit's (CPU) speed in megahertz (MHz). Megahertz is a unit of measurement commonly used to compare the speeds of computers.

The higher the CPU's megahertz rate, the faster it processes information and instructions.

Random Access Memory (RAM)

RAM is the computer's primary working memory.

RAM is used for short-term storage while the computer does its work. It is read/write memory.

RAM is distinguished from ROM, which is read-only memory. The more RAM you have the more your computer can do at one time.

RAM is volatile memory. It needs to be running to "remember" what it is doing. In case of a system failure or power interruption, you will lose all of your work in RAM that you have not saved on a disk drive. 

Memory Units

• Bit = smallest amount of info. 

• Byte = eight bits strung together. 

• Kilobyte (KB or K) = about 1000 bytes. 

• Megabyte (MB or meg) = about a million bytes. 

• Gigabyte (GB or gig) = about a billion bytes. 

Ram Vs. Hard Drive Storage

Computing Basics

Storage is where the program is kept, RAM is where it works.

To run today's popular programs, make sure your computer has adequate RAM and storage. 

Disk Drives

Disk drives allow you to store and move data from, and to, different types of media.

There are several types of drives: floppy drive, hard drive, CD-ROM drive, and DVD drive.

Floppy Drive

A floppy disk drive is an economical, removable storage medium. It uses a magnetic disk. You can record or erase it and then remove it from the computer. Today's floppy is 3.5 inches of square, hard plastic with a magnetic disk inside. 

Hard Drive

The hard disk, or hard drive, is your PC's main storage device. It's sometimes called the C:/ drive, and pronounced "cee" drive. Data is magnetically stored there. It stores programs and data files. 

CD-Rom Drive

CD-ROMs are compact discs, read-only, removable storage media. CD-ROMs read the data encoded on the disc and then transfer this data to the computer.

One CD-ROM can hold as much information as about 450 floppy diskettes (700 Mb).

Recently, gurus created the RW CD-ROM drive: re-writeable CD-ROM drive. It allows you to read, erase, and use it repeatedly like a floppy drive. 

Monitor

Sometimes we call the monitor a CRT (cathode ray tube) and sometimes we refer to it as a video display unit.

The monitor attaches to the video output of the computer and produces a visual display.

QWERTY Keyboard

It is the standard typewriter keyboard layout, used for computer keyboards.

It is the most frequently used input device for all computers.

The keyboard provides a set of alphabetic, numeric, punctuation, symbol, and control keys. 

Mouse

The mouse controls the pointer on your computer screen. It is housed in a palm-sized case. When you move it on your desk, the corresponding arrow, commonly known as the pointer, moves on the computer screen.

The flashing bar, known as the cursor, is where the work will take place on the computer screen. 

Expansion Slots

Your system has expansion slots so you can add additional hardware, known as peripherals or add-ons.

Some slots may already be taken for a sound card or video card.

Multimedia

Multimedia is a term used to describe any program that incorporates some combination of sound, music, written text, pictures, animation, and video. Almost all of the computers on the market today are multimedia capable. 

Printer

A printer is a device designed to print your computer-generated documents onto paper. Printers vary in their quality, speed, graphics capabilities, fonts, and even paper usage. The three most popular types of printers are dot matrix, ink jet (bubble jet), and laser printers.

• Dot Matrix. A dot matrix printer uses a print head and a ribbon to print a document. These printers are inexpensive and tend to be slow and loud. Their print quality is fair.

• Ink Jet or Bubble Jet. An inkjet printer works by spraying tiny dots of ink onto the paper. The print head controls the spray pattern to form the print. Excellent print quality at a reasonable price.

• Laser. A laser printer offers great quality and fast printing. It is also more expensive than the other two types of printers. 

DPI

DPI (dots per inch) is a measure of how good a printer is. The more DPI, the better the print, and the easier it is to read. 

Modem

A modem is the communications hardware that allows your computer to send and receive information from other computers, over a telephone line.

You will need a modem (and a telephone line) to hook up to online services and the Internet. 

Baud Rate

Baud rate is the number of times a modem's signal changes per second when transmitting data. It is how modem speed is measured. The bigger the number, the faster you can communicate.

DVD

DVD stands for digital versatile disk. 

DVD drives read DVDs. 

A DVD holds about 5 gigabytes of information while a CD-ROM only holds about 700 megabytes. 

A CD-ROM drive cannot read a DVD. However, DVD drives can read CD-ROMs.