Computers are electronic devices that can store, process, and output data. They have four basic components: input, processing, storage, and output. Data is raw unprocessed information that is entered into a computer. Information is the output produced after data is processed. The main components of a computer are the central processing unit (CPU), memory (RAM), and secondary storage devices like hard disks. Computers run operating systems and application software to perform tasks. The internet allows computers to connect globally to share information and resources.

1. Introduction to
Computers
Essential Understanding of
Computers and
Computer
Operations

2. Topics
 The term “computer” 
 Four basic computer operations 
 Data and information 
 Principal components of computer

 Data storage devices and usage 
 Software 
 The Internet & WWW 

3. What is a Computer?
 A programmable machine that inputs,
processes, and outputs information
 An electronic device for storing and
processing data
 Composed of hardware and software
 Can exist in a variety of sizes and
configurations

4. Examples

5. What Do Computers Do?
 Input, Process, Output, & Store data
Input Process Output
Store Data

6. Input, Processing, Storage,
and Output Devices

7. What is Data?
 The raw material of information
 Contain facts w/o interpretations
 The information entered into, and stored
within a computer or file
 Used by applications to accomplish tasks
 Unprocessed information
 E.g. text, numbers, images, audio, & video

8. What is Information?
 Contains meaning, knowledge, instruction,
communication, & representation of data
 Result of processing, manipulating and
organizing data in a way that adds to the
knowledge of the person receiving it
 The output of information systems

9. Flow of Computing


Data  Processing  Information
Example
Pat Brown
1001 Jump Street
Shoreline, WA 98123
$25 per hour 40 hours
Retrieve data
Calculate weekly wage:
$25 X 40 hours = $1000
Send information to
output device

10. Principal Components of
Computer
 Input devices
 System units
 Storage (memory) devices
 Importance of Saving
 Output devices

11. Input Devices
 Keyboard, mouse, scanner, & etc

12. System Units
 CPU (Central Processing Unit)
 Random Access Memory (RAM)
 Secondary Storage Devices

13. Central Processing Unit (CPU)
 Main processor of a computer that makes
everything work
 Interprets & carries out the basic instructions
 Performs all the instruction, logic, &
mathematical processing

14. Storage (memory) Devices
 Two types:
 Primary & Secondary
 Primary:

 Temporary memory for dynamic access by the
processor (CPU)
RAM (Random Access Memory)
 Secondary:
 For large data storage, e.g. hard disk drive
 RAM is much faster than disk drives for
dynamically interacting with the processor

15. Random Access Memory
(RAM) – the Primary Memory
 Temporarily stores instructions and data waiting
to be processed by the processor
 Memory units are measured in kilobytes,
megabytes, or gigabytes
 1 kilobytes = 1,000 bytes
= 1,000 memory locations ≈ 1,000 characters
 1 megabyte (MB) = 1 million memory locations
 1 gigabyte (GB) = 1 billion memory locations
 E.g. 512 MB = 512 million characters
1 MB can hold approx. 500 pages of text

16. Secondary Memory (Semi-
permanent)
 Magnetic Disks
 Hard disks, floppy disks, zip disks
 Optical Disks
 CD-ROM, CD-R (Recordable), CD-RW, DVD
 Flash Memory Cards
 USB flash drive: Small, lightweight, & large
storage capacity

17. Importance of Saving and
Saving Often
 When using an application, data is stored in
RAM temporarily
 When the file, application, or computer
closes, the data in the RAM is erased
 Where do I save the files?

 At the Lab: Removable disks such as floppy, zip,
or USB.
At home: Hard drive (C:) or any removable disk.
 Never remove a disk while the light flashes
 Saving on an existing file replaces the old
data with new (Save vs. Save As)

18. Importance of Data Backup
 All secondary storage devices such as floppy
and hard drive disks eventually fail, and you
lose the data
 Make backup files weekly, if not daily
 If you have a computer, use the hard drive or
a removable disk as your backup
 Otherwise, use the second removable disk

19. Output Devices



Printers
Monitors
and more

20. Personal Computers
 PC, Mac, and other microcomputers
 Desktop, Laptop, PDA
 Windows, Mac OS, Linux, etc.
 Increasingly more capable, portable,
affordable, and mobile

21. System Software
 Manages computer operations
 Instructs computer how to perform functions of
loading, storing, and executing an application
software and how to transfer data
 Examples: Windows, Mac OS, Linux, & etc.

22. Application Software
 Programs that tell a computer how to perform
tasks and produce information
 Categories:






Word processing Spreadsheet Database
Presentation graphics Web and Internet
access
Desktop publishing / image editing / multimedia
editing

23. The Internet and WWW


The Internet is the world’s largest network
Uses:





Send messages (e-mail) Access a
wealth of information Electronic
commerce
Online meeting
Access entertainment and multimedia
 WWW (World Wide Web)



The more popular component of the Internet
Web page: A document containing text, hyperlinks, images,
& other multimedia contents
Web site: A collection of Web pages

24. Communications Devices
 Modem
 Network card
 Router
 Wireless modem, network card, & router