-
Who owns the Internet?
- Individuals
- Universities
- Government agencies
- Private companies
-
Who manages the Internet?
- Nonprofit organizations
- User groups
-
Who pays for the Internet?
- U.S. taxpayers
- Businesses
- Universities
- Other countries
-
Types of servers
- Web servers
- Host Web pages
- Commerce servers
- Enable the purchase of goods and services over the Web
- File servers
- Provide remote storage space for files that users can download
-
Circuit Switching
- Dedicated connection between two points
- Remains active until the transmission is terminated
- Used in telephone communications
- Inefficient for computers
-
Packet Switching
- Data is broken into small units (packets)
- Packets are sent over various routes to their destination
- Packets are reassembled by the receiving computer
-
Packets contain:
- Destination/source addresses
- Reassembling instructions
- Data
-
Transmission Control Protocol (TCP)
- Prepares data for transmission
- Provides error checking
- Enables resending lost data
-
Internet Protocol (IP)
Responsible for sending data from one computer to another
-
IP Address
Unique number that identifies each device connected to the Internet
-
Classless interdomain routing (CIDR)
- Allows a single IP address to represent several unique addresses
- Uses a network prefix (slash and number)
- Identifies how many bits in the IP address are unique identifiers
-
Domain Names
- Names that take the place of an IP address
- Sample domain name: www.mywebsite.com
-
Domain Name System Servers
Internet servers that translate domain names into IP addresses
-
HyperText Markup Language (HTML)
- Tags that describe the formatting and layout of a Web page
- Not programming languages, but sets of rules for specifying how a browser should display text
-
Extensible HyperText Markup Language (XHTML)
- Successor to HTML
- Much more stringent rules regarding tagging
-
Extensible Markup Language (XML)
- Designed for information exchange
- Can be used to create your own markup language
- Used in e-commerce transactions
- Custom packages for specific communities
- MathML, Wireless Markup Language (WML)
-
Common Gateway Interface (CGI)
Browsers request that a program file executes (runs)
-
Dynamic HTML
- A combination of technologies
- HTML/XHTML
- Cascading style sheets
- JavaScript
- Allows a Web page to change in response to user action
- Brings special effects to otherwise static Web pages
-
Cascading Style Sheets
- Statements that define in a single location how to display HTML/XHTML elements
- Enable a Web developer to define a style for each HTML/XHTML element
- The rule can be applied to as many elements on as many Web pages as needed Speeds up global changes
-
Document Object Model
- Organizes the objects and elements of a Web page
- Defines every item on a Web page as an object
- Developers can easily change the properties of these objects
-
Client-Side Applications
Programs that run on a client computer with no interaction with the server
-
E-mail security
- Encryption
- Private-key encryption
- Public-key encryption
- Secure data transmission software
- SafeMessage
-
Voice over Internet Protocol (VoIP)
- Allows inexpensive or free long-distance phone calls over the Internet
- Some cell phones are VoIP enabled
- Uses packet switching
-
Cloud Computing
- Uses Internet to deliver business services online
- Used by many Web 2.0 applications (blogs, wikis, social networks) and Web-based e-mail
- Requires a large investment of hardware, software, and programming talent
|
|
