Computer Components and Terms

Computer Components and Terms

Turning on a Computer and Using a Mouse

	Monitor The monitor displays the text and graphics generated by the computer.
	Keyboard The keyboard allows you to enter information into your computer. It is similar to a typewriter but has some different keys that perform special functions.
	Mouse The mouse is a pointing device that allows you to select and manipulate objects you see on your monitor.
	Floppy Disk Floppy disks go in the A: drive of your computer. They are removable storage on which your computer can read or write files. Floppy disks are approximately 3 1/2 inches in size and hold 1.4MB (1,400,000 bytes). While these disks don't seem floppy like their name would suggest, there is a disk inside, which is floppy. The disk is encased in a hard plastic case to protect it.
	CD-ROM CD-ROM disks are inserted into your system's D: drive. They can store much more information than a floppy disk, but your computer cannot write to them. This is because they are Read-Only Memory (ROM).
	Hard Disk (C:drive) The hard disk is located inside the CPU and is similar to a floppy disk. The only differences are it cannot be removed, can store more data or files, and contains important files or programs.
	Printer The printer prints text and pictures you create on your machine.
	Speakers or Headphones Headphones and speakers allow the user to hear the audio portion of a program.
	Central Processing Unit The unit houses the brain of your computer, including the memory, power supply, and central processor. All other components are considered peripheral.

Windows Desktop
The windows desktop contains various icons, which access programs operating in the Windows operating system. An icon is a symbol or graphic representing a program or command.
To move around the Windows Desktop, use the mouse. The mouse will move the arrow on the screen.

Hardware
Hardware is the tangible computer equipment such as a CPU, keyboard, mouse, monitor, etc.

Software
Software is the computer programs, routines, and symbolic languages that control the function of the hardware, such as Windows, Word, Excel, etc.

Memory
Memory is the internal storage areas in the computer. The term identifies data storage that comes in the form of chips, and the word storage is used for the memory that exists on tapes or disks. Moreover, the term memory is usually used as shorthand for physical memory, which refers to the actual chips capable of holding data. Therefore, memory is both hardware and software.

Read-Only Memory (ROM)
ROM is computer memory on which data has been prerecorded. Once data has been written on a ROM chip, it cannot be removed and can only be read. ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile. Most personal computers contain a small amount of ROM that stores critical programs such as the program that boots the computer. In addition, ROM is used extensively in calculators and peripheral devices such as laser printers, whose fonts are often stored in ROM.

Random-Access Memory (RAM)
RAM is a type of memory that can be accessed randomly and is the most common type of memory found in computers and other devices, such as printers. Also called the main memory.

Operating System
An operating system is the program (software) on top of which all programs run. It controls or operates the system and the relationships of the hardware and software. Windows is an example of an operating system.

Windows
Windows is an operating system. It is a multi-tasking environment and is a graphical user interface (GUI) that uses windows.
windows
A window is an element of Windows and contains other computer programs, which operate independently of each other. Information can be shared between windows. Windows have frames and contain minimize, resize, and close buttons in the upper right corner.

Windows Buttons
There are buttons on the screen, which enable you to perform commands within a window. Buttons usually are smallish gray squares that contain an icon. buttons are activated by moving the mouse pointer so that the tip of the pointer is pointing to the center of a button, then click the mouse.

Three buttons found on almost every window are the minimize, resize, and close buttons. these are found in the upper right corner of each window. The minimize button allows you to minimize or set aside a program, so it remains open or active, but allows you to see the Windows Desktop. The resize button (also called the maximize or restore button) allows you to change the size of the window on the screen. The close button closes the window and program. You would need to restart the program if you click on the close button.

Screen Saver
A screen saver will appear on the screen when the computer remains idle for a certain period of time. the purpose of a screen saver is to save the screen from prolonged use, which will shorten the monitor's life. A screen saver can be anything from a picture, to scrolling words, moving images, black, etc. The information you were viewing on the screen remains in its original location and state. To make the desktop reappear, move the mouse or press a key on the keyboard.

Storage Devices
Bits and Bytes
A bit is short for binary digit. A bit contains a single value of 0 or 1. A consecutive group of bits makes up a unit. For instance, there are 8 bits in one byte. A byte is more commonly referred to when discussing space. A byte represents a single character. (For example, there are 10 bytes in the phrase, I love you. This is because there are 8 letters and two spaces between the three words.) There is a finite amount of space on a computer and disk. Bytes are commonly identified in thousands, millions, and billions:

KB for a thousand bytes

MB for a million bytes

GB for a billion bytes
These are pronounced kilobytes (KB); megabytes (MB); and gigabytes (GB).

Other types of CDs
There are two other types of CDs available on the market. A CD-R (compact disk recordable) is a CD that will record information, such as files or music. It can only be written to once. Also, once information is placed on the CD, it cannot be removed or altered.

A CD-RW (compact disk re-writable) is a CD which can have information placed on it. That information can later be altered. CD-Rs and CD-RWs can only be written to in CD-RW drives. CD-RW drives both read and write. CD ROM drives only read CDs (any type).

Storage Device Organization
CDs and disks are both circular in shape. They spin on an access, which allows data to be read off the disk at a rapid rate. Your files are saved on the disk in the order they are entered.

When you make a file bigger, part of the data resides where it was first saved and the remainder is saved after other data. In other words, part of our file would be located in one part of the disk and another part would be located in another part.

Files
A File is a contiguous group of bytes. For instance, your resume would be contained in a single File. Every File must have a name. Filenames cannot contain the characters* | \ < > " ? /

Files are also designated by their type. For instance, your resume may have been created in Microsoft Word, but your budget may have been created in Mocrosoft Excel. Files are given an extension, such as .doc, .xls, .pdf, .jpg, .bmp. The extension is located after a period, which is placed between the extension and the filename.

You do not have to type the extension or period when naming a file. The computer program you are working in will perform this operation for you.

Examples of filenames would be:
filename.doc
vacation.ppt
Letter to Mother.doc
Monthly Budget.xls
Dog.bmp

File Storage
Files are stored on disks. The floppy disk (called "floppy" because inside the plastic casing there is a flexible disk) is placed in the A: drive and the hard disk inside the computer is generally the C: drive.

Folders
Folders can be created on storage disks to help organize information. Folders have an icon resembling a file folder. An example of a folder is "My Documents."

"My Documents" folder is located on the hard disk C:. In most computer programs, "My Documents" is the location where files will be stored.

If you want to change the location of where files will be stored, you must make sure that the disk you would like to store your information on is the designated disk.

Turning on the Computer
To turn on the computer, press the power button on the front of the CPU. The power button has this symbol. Depress the button and the computer will begin to boot up. The term boot up refers to the loading of the operating system and other basic software. The procedure also determines what peripheral devices are connected to the computer.

Other Equipment
The monitor must also be powered along with any other peripheral devices (such as a printer or scanner), other than the keyboard and mouse. The keyboard and mouse receive power from the CPU.

Lights on the Front
Green lights indicate that the power is on and the equipment is running.
Orange lights indicate that the equipment is in a low-power or sleep mode. The equipment is still on but not running.

Note: Computers should be plugged into a surge protector (suppressor) or UPS (uninterruptible power supply). A surge protector protects the computer from power surges that can occur in electrical lines. An UPS has a battery that will maintain power for a period of time in the event of a power outage. This enables the user to shut the computer down properly before the discontinuation of power from the source.

Mouse Operation
Holding the Mouse
Rest your hand on the mouse so that your forefinger and middle finger are resting on the left mouse button and right mouse button, respectively. Your thumb and ring and pinky fingers will rest on the sides of the mouse, and your palm will rest on the remaining portion of the top of the mouse. Do not grip the mouse. Rest your wrist on the table.
Moving the Mouse
The mouse should be placed on a flat surface or mouse pad, trackball facing down and buttons facing up. The mouse cursor moves when the track ball is moved across a flat surface. If the ball does not roll, the mouse cursor does not move. Try lifting the mouse off the pad and setting it down at the other side of the pad. The mouse cursor position will not change.
Mouse Buttons and Operation
Click
Press the left mouse button once with your forefinger, which is resting on the button. This will move the text cursor to that location on the page.
Double-Click
Rapidly click the left mouse button twice. This is often done to select a word or open a program.
Click and Drag
To drag means to hold down the left mouse button and move the mouse on the pad. Example: To highlight or select text, click (single click, left button) where you want to begin. Drag the cursor to the end of the desired text. Release the mouse button. The text is now selected. To select one word, double-click it.
Drag and Drop
Some items can be moved by clicking the item, holding down the mouse button, and dragging the item to a new location.
Right-Click
Click the right mouse button once for context-sensitive functions.
Scrolling
Scrolling means moving up and down within a web page or other computer window. This is done by using the mouse to move the elevator up and down within the scroll bar at the far right of this screen. You can do this three ways:

To move one line at a time, click on the up arrow at the top of the scroll bar or the down arrow at the bottom.

To move one screen at a time, click on the empty space within the scroll bar, above or below the elevator.

To move anywhere within the document, point to the elevator itself. Press and hold down the left mouse button. Now you can slide the elevator up or down by moving the mouse on the mouse pad. Release the button when you are in the desired location.

Type of Click	How to Perform Click	When to use Click
Click	One click of the left mouse button	To select an image or icon To move items around the computer's desktop To navigate the cursor through a word processing program
Double-Click	Two clicks of the left mouse button	To execute an action such as opening a program
Right-Click	One click of the right mouse button	To expose shortcuts in a variety of programs