Transcript Unit A: Computer and Internet Basics

Computer and
Internet Basics
Unit A
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Objectives
Define Computers
Explore Computer Functions
Categorize Computers
Examine Personal Computer
Systems
Explore Data, Information, and
Files
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Objectives
Introduce Application and System
Software
Define Internet Basics
Connect to the Internet
Understand World Wide Web
Basics
Use Browsers
Understand E-mail Basics
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A Computer is a device that
accepts input
processes data
stores data
produces output
(all according to a series of stored instructions)
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Computer system consists of:
Hardware:
microprocessor
Peripheral devices:
input and output
Software:
programs
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Computer Network
Two or more
computers that are
connected and
share data and
programs
LAN is a local area network
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Computer Functions
Input
•Words, symbols, numbers, sound,
pictures, program instructions
•Program calculates, sorts modifies data
Process
•Uses microprocessor or CPU
Output
Store
•Results of processing
•Reports, graphs, documents, pictures
•Printer or monitor
•Memory is temporary holding area (RAM)
•Storage is permanent (disk)
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Categorizing Computers
Cost
Usage
Size
Capability
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Computers to Fit Every Need
Five basic categories
– Mobile devices
– Personal computers
– Midrange servers
– Mainframe computers
– Supercomputers
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Mobile Devices
Very small computing devices.
Usually based on a wireless
phone
or pager.
Many can be used to access email
and Web pages.
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Less Powerful Computers
•Handheld computer/PDA
•PC/microcomputer
•Workstations
•Videogame console
–Sony PlayStation®
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More Powerful Computers
Server
– Supplies network computers with data
Mainframe
– Large, expensive, powerful, many users
– Reliability, data security, central control
important
Supercomputer
– Fastest and most powerful
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Personal Computers, Cont’d.
Desktop computers—small
enough
to fit on or next to a desk. Can
use:
– Desktop case
– Tower case
– All-in-one case
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Personal Computers, Cont’d.
Portable PCs—designed to be
carried around.
– Notebook computers
– Tablet PCs (either slate or convertible)
– Handheld computers (pocket
computers)
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Personal Computers, Cont’d.
PCs designed for just network
use are referred to as network
computers (NCs) or thin
clients.
Devices designed just for
Internet access are called
Internet appliances.
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Midrange Servers
Medium-sized computers, also
called minicomputers or midrange
computers.
Fall between microcomputers and
mainframes in processing power.
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Mainframe Computers
Standard choice for most large
organizations.
Specialize in high-volume
processing of business
transactions.
Also called high-end
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Supercomputers
Used for applications that have
extraordinary demands for
processing power.
Offer very fast speeds and
extreme degrees of accuracy.
Commonly created today by
connecting hundreds of
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Computer System
Peripherals
Computer +
input devices + output devices + storage devices
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System Unit
Power Supply
Storage Devices
Circuit Boards
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Input/Output Devices
Monitor
Keyboard
Mouse
Modem
Printer
Speakers/sound card
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Storage Devices
Floppy disk drive
Hard disk drive
CD-ROM drive
DVD drive
CD writer
DVD writer
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Data vs. Information
Data (symbols) used by computers
Information (meaningful) used by people
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Software
The programs or instructions
used to tell the computer
hardware what to do.
System software allows a
computer to operate and run
application software.
Application software performs
specific tasks or applications.
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Data and Information
Data = raw, unorganized facts.
– Can be in the form of text, graphics,
audio, or video.
Information = data that has
been processed into a useful
form.
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Computer Users and
Professionals
Computer users, or end users,
are the people who use a
computer to obtain information.
Programmers are computer
professionals whose job it is to
write the programs that
computers use.
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Data
Binary number
system to define
electronic data
0 or 1
Bit
Byte (8 bits)
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Files
Collection of data on a storage
medium
Data file (passive)
Executable file (active)
Filename and extension
Image.jpg
Word.exe
Resume.doc
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System Software
Helps the computer monitor itself
in order to function efficiently
Operating system
– Master controller of all computer
activities
Popular operating systems
– PCs: Microsoft Windows, Mac OS
– Handhelds: Windows CE and Palm OS
– Servers: Linus and UNIX
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Platform
Microprocessor + Operating system
Mac and PC compatibility is an
issue
Apple computer = Mac platform
Original IBM computer =
Windows or PC platform
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Application Software
Microsoft
Excel
Microsoft
PowerPoint
Designed
to carry out
a particular
task
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Internet Basics
Internet is a
collection of local,
regional, national
and international
computer networks
that are linked
together to
exchange data and
distribute
processing tasks.
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Internet Terminology
Backbone: defines main Internet
routes
– Constructed and maintained by major
telecommunications companies
TCP/IP:
– Transmission Control Protocol/ Internet
Protocol
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Internet Terminology
Server software
IP Address: unique
number for each Internet
computer
Packets: small chunks of
data ready to travel the
Internet
Router: helps send along
the packets to correct
destination
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Internet Resources
Internet Telephony
Usenet
E-commerce
Instant Messaging
Web Sites
E-mail
Internet Radio
Download Or Upload
Chat Groups
P2P file sharing
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Modem Internet Connections
Dial-up connection via modem
(56K)
Cable modems
– Network card and cable modem required
– Always-on and 25 times faster than dial-up
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Faster Internet Connections
ISDN (Integrated Services Digital
Network)
– 64K or 128K
– Always-on and expensive
DSL (Digital Subscriber Line)
– Up to 125 times faster than dialup
DSS (Digital Satellite Service)
– 500K
Need proximity to a telephone switching station
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Internet Service Provider (ISP)
Provides internet access to
businesses, organizations and
individuals
Provides telecommunications
equipment
User ID and password required
Connects you to backbone
E-mail account monthly fee
Should have local access telephone
numbers
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World Wide Web Basics
Files interconnected via hypertext
Web pages make up a web site
Home Page
Links or hyperlinks
Web servers
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World Wide Web Basics
URL
– No spaces and Case sensitive
– HTTP (Hypertext Transfer Protocol)
HTML (Hypertext Markup
Language)
– .htm or .html file extension
http://www.cnn.com/showbiz/movies.htm
Web
protocol
standard
Web
server
name
Folder
name
Document name
and filename45
extension
Search Engines
Keywords
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Using Browsers
Can type URLs
HTML tags tell browser how to display web
page data
Back, forward and stop buttons
Setting a home page
Print and copy options
History list
Favorites and bookmarks
Edit and Find
Microsoft Internet Explorer® and Netscape Navigator®
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E-mail Basics
Account = Mailbox
Message
userid@computer
Attachment
Most use HTML format
Netiquette
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E-mail System
E-mail servers
Store-and-forward technology
Types
– POP (Post Office Protocol) used via ISP
– IMAP (Internet Messaging Access
Protocol)
– Web-based like Hotmail
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E-mail System
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Computer and
Internet Basics
End
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