Introduction to Computers: Networks and the Internet

Computer Networks

A computer network, or simply a network, is a collection of computers and other hardware interconnected (wired or wirelessly) that allows sharing of resources and information.  Traditionally, networks were only used in businesses, but home networks are becoming very commonplace to share resource such as disk space, printers, Internet connections and access to software.

“In 2010, 8 out of 10 Canadian households (79%) had access to the Internet. Over one-half of connected households used more than one type of device to go online.”  (Canadian Internet Use Survey – Statistics Canada – May 2011).

There is a proliferation of networked devices; almost every new electronic gadget includes networking capabilities, allowing for integration of devices within the home (printers, televisions, stereos, video gaming) and online services – such as the immensely popular Netflix.

A router connects all the computers (and devices) on a local area network (LAN) together and shares a single Internet connection between the devices. The router assigns each device on the network with a unique identifier called an IP address.  The addresses usually are in the range of 192.168.x.x where x means any number between 0 and 255.  File and print sharing must be enabled on the computer that will share its resources with other devices on the network.

Wireless local area network (WLAN or Wi-Fi devices) such as a personal computer, video-game console, smartphone, tablet, or digital audio player, can connect to a network resource such as the Internet via a wireless network access point. Such an access point (or hotspot) has a range of about 20 meters (65 feet) indoors and a greater range outdoors. Wi-Fi can be less secure than wired connections (such as Ethernet) because an intruder does not need a physical connection. Because of this, Wi-Fi has adopted password-based access. The early security standard WEP, proved somewhat insecure. Higher quality protocols (WPA, WPA2) were added later.

Networks can also be open to remote secure access through a virtual private network. A VPN allows a computer to connect to a computer or network through the Internet and is often used by businesses to grant safe remote access to employees.

File Transfer Protocol (FTP) allows users to transfer files and documents from one computer to another (or to/from a website server to a computer). There are a few different software programs that will make this process quite simple including the popular Open Source application FileZilla. If you are designing a website you may need to use ftp to update your website. 

The Internet

The Internet or the “Net” is a collection of computers, all linked together, to share information globally. It is a network of networks that consists of millions of private, public, academic, business, and government networks, that are connected by a broad array of technologies. The Internet carries an extensive range of information resources and services, the World Wide Web (WWW) and the infrastructure to support email.

It was first developed in the U.S. by two universities who were both working on the same contract and wanted to share their data. They were faxing information back and forth and then retyping it until they came up an easier way to share.  The Internet was born and has mushroomed outward from that point.

“Among Internet connected households, most used a desktop computer (71%) or a laptop computer (64%).  Over one-third (35%) used a wireless handheld device to access the Internet from home.  A majority (54%) of connected households used more than one type of device to go online in 2010.” (Canadian Internet Use Survey – Statistics Canada – May 2011).

Internet Browser

An Internet browser is a program designed to enable users to access, retrieve and view documents and other resources on the Internet. It allows users to maneuver around (surf) the Internet and view web pages. Some of the more popular browsers are Mozilla Firefox, Apple Safari, Opera, Google Chrome and Microsoft Internet Explorer.  All these programs perform essentially similar functions.

The World Wide Web is a collection of web pages connected together with hyperlinks. Each document or page has a unique address that allows you to find it among the millions of other documents on the Web. The web address is called a Uniform Resource Locator (URL). When you chose a new link by clicking on it or by typing it into the address field, your browser sends a request for that document and displays it on the screen. That link can be to a different section of the current document, another document on the same website as the original or on another website anywhere in the world. Web pages are designed using hypertext markup language or HTML.

The power of the web is the almost unlimited links to unique, useful or interesting pages – there is something for everyone! Internet users collect links to their favorite sites or web pages and locally store them to a bookmark or favorites list.

Receiving information, such as a web page, from another computer is called downloading. Sending information to another computer is called uploading. Being Online means being connected to the Internet.  An Internet service provider (ISP) is a company that provides access to the Internet.

Search Engines

Search Engines make finding things on the Internet easy. Search engines are run by companies that collect, sort, categorize and present information from web sites to the user based on keyword searches or through directory listings.

The results from a search are a list of pages with links to the documents that match your search. Generally you will see a list with the title of the page and the matching search terms. You may also see a short description of that web page. Clicking on the title will take you to that page.

It is worth taking some time to learn how to make an effective keyword search, as the sheer amount of information that these search engines provide can be overwhelming. By narrowing your search to a specific phrase you can target your searches more effectively.  Often if you don’t see what you are looking for in the first page of results, you may want to rephrase your search.

Each search engine will display different results and sort those results uniquely. If you don’t find the information you want on one search site, you can try another. Although there are hundreds of search engines on the Internet, the majority of people only use a few.   There is a reason Google has become a verb!

Email

An email program controls sending, composing and receiving email. Most email programs can also be used to read postings on newsgroups. Email is the electronic equivalent of sending a letter through the mail. There are many different mail-reading programs (clients) that control email but the basic functions are all the same.

An email address directs a message to the recipient.  Email addresses are made up of an account name + the ‘@’ symbol + the address of the email provider, in the format:  account@emailhost.com.

As well as sending and receiving mail, the recipient can:

  • Save the address for future reference in an address book
  • Reply to the original message
  • Forward the message to a third party
  • Edit a message
  • Check the spelling and a wide range of other options.

Trav’s Tips:  One of the services provided by your ISP is to provide a ‘free’ email address and mailbox (such as yourname@aliant.ns.ca or yourname@eastlink.ca, etc.).  This is somewhat self-serving for the ISP, as you will lose this address (or have to pay to keep it ongoing) if you ever decide to change your service provider.  Using a free, Internet based email server such as Hotmail or Gmail makes your ISP choice irrelevant, and will always keep your address. Note:  Most ISP’s also offer web mail programs so that you can log on to check and send email using any Internet accessible computer – offering similar services to, but likely limited when compared to solely online services (Hotmail, Gmail, etc.). 

An email message is made up of two parts: the header information and the body. The recipient’s address (to), the subject, and the sender’s email address are contained in the header. The content of the message is in the body.

Email can be composed and sent as plain text or HTML format. Plain text messages can be read by any email client but most modern email clients can compose and display HTML email documents containing formatting (such as bold or italicized), different fonts (size and color), backgrounds, etc.

You can also attach files to email messages to send picture, sound, documents, videos and other types of files with your email. Many email programs automatically open attachments such as photos and web page code.  Depending on the email provider, there are various limits to how large a single email can be (including attachment size), however less than 10 Mb per email is a good rule of thumb.

Unrequested or spam email has become a problem on the Internet. Most email providers use software that filters out the worst of this junk mail.

Messaging & Chat

Instant Messaging (IM) and communication software allows users to find friends and contacts through the Internet and communicate with them in real time (through text, voice and/or video). Users maintain a list of contacts, which the software will notify when they are online and contact is available. Text-only services (ICQ, IRC, MSN Messenger, AIM, etc.) have decreased in popularity since the creation of text messaging on cell phones, free video chatting and social networking tools.

Social Networking

Social Networking has become a very large part of the Internet. Facebook, Twitter, Pinterest and other services provide areas for people to communicate ideas, share photos, and keep in touch. YouTube, Vimeo, Flickr and other media services provide space for people to share their videos and photos.

A 2012 Pew Internet survey found that 65 percent of Internet users use social networking sites.  Sixty-one percent of adults under 30 reported that they used a social networking site at least once on a typical day while daily usage among Internet users aged between 50-64 rose sharply from 20 percent in 2010 to 32 percent in 2011.

To access these services you will need to register for an account. Once you have logged in with your personal username and password you can access the resources that these services offer.

ECommerce

Electronic Transactions, including paying bills, making purchases and banking on the Internet are also becoming commonplace. The popularity of sites like Ebay and Etsy has shown that anything can be bought and sold with the click of a button (and of course, a credit card). The primary concern of these enterprises is to maintain security.

The Internet, by its nature, is an open system that means that information can flow freely from one computer to the next. Information transmitted through the Internet can be intercepted and copied as any point along the path. For this reason it is not a good idea to send confidential information like credit card numbers through the Internet the same way you might send an email to a friend. In order to send confidential information you must be sure that your private information cannot be intercepted along the way.

The most common security method used on the web is Secure Sockets Layer (SSL). A website creates a secure connection to your computer, which ensures that all the information that enter and is not accessible to anyone else. If information from a secure connection is intercepted it will be encrypted making it useless to persons with malicious intent.  Encryption uses a complex mathematical formula and is reassembled or decrypted at the intended other end.  Anyone with criminal intent who intercepts your transaction will be treated to a stream of garbled nonsense – (e.g.. qANQR1DBwU4D560EJv6XqrMQB)! 

Network and Internet Learning Check 

  1. T or F              A router is used to connect multiple networked devices to each other and the Internet.
  2. T or F              Multiple devices can share the same IP Address on a Local Area Network.
  3. T or F              WPA security is preferable to WEP when setting up your own hotspot.
  4. T or F              Web addresses are also known as URLs.
  5. T or F              Sending data from one computer to another is known as downloading.
  6. T or F              Your message text is located in the header of an email.
  7. T or F              Plain text emails can contain different fonts.
  8. T or F              Encryption is a standard form of computer security.
  9. T or F              HTML is a common form of security on banking websites.
  10. T or F              A VPN is sometimes used for someone working at home to safely access computers located remotely at their business.