Computer network: A collection of hardware and other devices that are connected together.

Computer network:
A collection of hardware and other devices that are connected together.

• — Users can share hardware, software, and data
• — Users can communicate with each other

• Network servers: Manage resources on a network
• •      Clients: Access resources through the network server
• •      Computer networks exist in many sizes and types
• — Home networks
• — School and small business networks
• — Large corporate
• — Public wireless networks
• — The Internet

Internet and World Wide Web

• Internet: The largest and most well-known computer network in the world
• Individuals connect to the Internet using an Internet service provider (ISP)
  • World Wide Web: One resource (a vast collection of Web pages) available through the Internet
  • Web sites contain Web pages stored on Web servers
  • Web pages viewed using a Web browser (InternetExplorer, Safari, Firefox, Opera, etc.
    • A wide variety of information is available through theWeb

Accessing a Network or the Internet

• Need a modem or network adapter
• Some networks require a username and password
• Internet connections can be:
• —  Direct (always-on) connections
• —  Dial-up connections

Internet Address

• Internet addresses are used to access resources on the Internet
• IP address: Numeric address that identifies computers (207.46.138.20)
• Domain name: Text-based address that identifies computers (microsoft.com)
• Uniform resource locator (URL): Identifies Web pages (http:IIwww.pbskids.org)
• E-mail address: Identifies people for e-mail exchange (jsmith@cengage.com)

IP Addresses and Domain Names

• IP addresses are numeric and unique
• Domain Names: Correspond to IP addresses
• — Top-level domains (TLDs) identifies type of organization or its location

Uniform Resource Locators (URLs)

• URL: Uniquely identifies a Web page
• Consists of:
• — Information identifying the Web server
• — Names of folders in which the Web page files are stored
• — Web page’s filename
  • Protocols:
  • — Hypertext Transfer Protocol (http) is typically used to display Web pages (https is used for secure Web pages
  • — File Transfer Protocol (ftp) is often used for file exchange

E-Mail   Addresses
E-mail addresses consist of:

• — Username: A persons’ identifying name for a particular domain
• — The @ symbol
• — Domain name for the computer that will be handling the person’s e-mail (mail server)

Surfing the Web
Web browser: Used to display Web pages

• Browser home page: The first page displayed when the browser is opened
• To load a Web page, you can:
• — Type a URL in the Address bar
• — Click a hyperlink on a displayed Web page
• — Select a FavoritelBookmark or page from the History list

Searching the Web

• Search site: Web page that helps you find Web pages containing the information you are seeking
• — Typically search using keywords
• •      Reference sites: Look up addresses, telephone numbers, ZIP codes, maps, etc.

E-Mail
Electronic mail (e-mail): electronic messages exchanged via a private network or the Internet

• — Can be conventional or Web-based
• — Can contain photos, attached files, etc.

Computers and Society
The vast improvements in technology over the past decade have had a distinct impact on daily life, both at home and at work

• Many benefits of a computer-oriented society
• Also risks
• — Computer viruses
• — Identity theft and phishing
• — Privacy issues
  • Differences in online communications
  • The anonymity factor
  • Information integrity (not all information on the Internet is accurate)