CIS 150 – Introduction to Computer Applications
CIS 150 – Introduction to Computer Applications
Internet Concepts Class Notes
These notes are to accompany the Internet Concepts PowerPoint Presentation. Please refer to these notes when viewing the presentation.
Slides 2 & 3 identify the major objectives of this presentation and these notes.
Slide 4: The Internet is a global network that connects millions of computers around the world that all work together to share information. The main benefits of the Internet are that it is interactive, immediate, and global. That means that you can access the information that you need right now, no matter what day or time it is, from virtually any place in the world. You don’t have to wait for the library to open, to send you an interlibrary loan, etc. As of 1999, there were more than 200 million users, with that number growing dramatically every year. The Internet started in the 1960’s as a joint effort by government and education to provide linked computer support in the case of a nuclear attack. This effort was referred to by the name ARPAnet. The Internet is not owned by any one agency or government, therefore, it is very difficult to establish authority over the content or even state the precise size.
Slide 5: To connect to the Internet, or the WWW, there are three components needed: communications capability, access to the Internet (network access) through an Internet Service Provider – ISP, and software. Communications capability refers to a modem or a network hookup. A modem is a hardware device that allows computers to communicate with each other via telephone lines or cable access. The modem (which is short for modulator / demodulator) changes digital signals that are created by your computer into analog sound signals that can be transmitted across the telephone hookups. The receiving computer must then change the analog sounds back into digital signals that the computer can understand. Modem speed is measured in bits per second (BPS). This is the speed at which it can pass the data back and forth. Your book describes other types of communications capabilities including Ethernet cards and network connections. The second component an Internet Account from an Internet Service Provider (ISP). From your home, you can use a commercial ISP such as America Online (AOL), Microsoft Network (MSN), Prodigy, or numerous local providers. Many providers have unlimited access plans for a set price per month. The third component needed is software. The software is needed to instruct the computer on how to dial and access the system, network, or Internet. These capabilities are build into the Windows system software.
Slide 6: The World Wide Web (WWW) is a subset of the Internet. The WWW is a system of Internet servers located all over the world that supports specially formatted hypertext or hypermedia documents. A hypertext document is a document formatted in a script called HTML (Hypertext Markup Language) that supports links to other documents – called hyperlinks. These links allow you to jump from one document to another by clicking on the “hot spot” or hyperlink. These documents do not have to physically reside on the same computer or even in the same country, they just have to be available on a WWW network server computer. A hypermedia document is a hypertext document that contains items besides text – graphics, audio, video, etc. The WWW allows access to an enormous amount of information such as weather reports, sports statistics, movie reviews, reference information for term papers, research for classes, government information, online courses, and much, much more. Not all Internet servers are part of the WWW. There are other types of documents and access available on the Internet that is not on the WWW – FTP and Gopher sites are examples of these types of services.
Slide 7: Many terms are used when explaining the WWW. HTTP stands for Hypertext Transfer Protocol. Protocols are rules and/or regulations that govern a computer system. Therefore, HTTP is the protocol that governs the WWW, how web documents are transferred between machines. HTTPS allows for secure document transfer between machines. HTML is, as previously stated, the language in which are web documents are created. This is necessary because Web Browsers are the software packages that display the hypertext or hypermedia documents that make up the WWW and Web Browsers are written to interpret the HTML documents and display them. TCP/IP stands for Transmission Control Protocol / Internet Protocol and it is the protocol that allows communication to take place between different types of machines that may be operating on different types of operating systems. For example, through the use of TCP/IP a desktop machine running the Windows system can communicate effectively with a Macintosh laptop or a server running in a UNIX system environment. This was a very important development for the functionality of the Internet. A URL is a Uniform Resource Locator. It is the addressing system for finding information on the WWW. There will be more details on the URL beginning with slide 12. Tim Berners-Lee is the person who developed the URL addressing system, HTTP, and HTML. He made these developments available to the public at no charge, which allowed for the development of the WWW. Web pages must be stored somewhere with constant internet availability for them to accessible. Computers that store the hypertext and/or hypermedia documents and make them available to other computers are called Web Servers. Web Clients are the personal computers, or other computers, that access the files held on Web Servers. The owners of the files have made their files publicly available for clients to access. In order to navigate the web, you need a Web Browser, this is a software application that is used to locate and display web pages. The two most popular browsers are Microsoft Internet Explorer and Netscape Navigator. Both of these are graphical browsers, which mean they can display graphics as well as text. In addition, most browsers can present multimedia information such as sound and video.
Slide 8: WWW documents, known as Web Pages, must be viewed though a Web Browser program. Just as in other Windows programs, the web browser programs use a graphical user interface (GUI). Microsoft Internet Explorer is an example of a Web Browser program. Standard Windows program components that are found in other Windows applications will also be found in Internet Explorer (IE).
➢ Menu Bar – The menu bar will feature all of the typical Windows menu options.
➢ Toolbar – The tool bar gives you access to commands via buttons
o Home Button – This will bring you to your specified Home Page (unless you specify a different web page to be your Home Page, the browser will load its original home page
o History Links – This contains the web pages that have been most recently visited
o Back Button – This will display the previously viewed web page
o Forward Button – This will display the next web page viewed in a series of previously viewed web pages (you cannot view forward pages unless you have gone backwards)
o Reload / Refresh Button – When this button is clicked the browser software will reconnect to the web server to see if there have been any changes to the currently displayed web page since it was loaded into the computer’s memory
o Stop Button – The stop button will stop web page transmission from the server
o Favorites / Bookmarks – The favorites and bookmarks allow you to store and organize lists of the addresses of web pages that you visit frequently so you don’t have to find and/or enter the web address again
o Address Line – The address line is where you will enter the URL, web address, of the web page that you wish to display in your browser.
➢ Title Bar – The title bar displays the name of the Web Browser program and the name of the open web page
➢ Scroll Bars – Scroll Bars will allow you to view parts of a web document quickly and easily
➢ Status Bar – The status bar will display the name of the web page that is loading, load status, and any other messages to the user
Slide 9: This slide shows you a screen shot of the web site for the textbook for this class. There are many additional features that you can benefit from located at this site, such as online study guides and sample test questions. This screen shot is viewed through the Internet Explorer web browser with the appropriate URL typed into the address bar to display the web page
Slide 10: As previously stated, hyperlinks are used in web pages to link to other documents, which may include text, graphics, sounds, or video links. When looking at a web page, the standard indicator a hyperlink is that the text will appear in blue and will be underlined. This indicates a hyperlink that has not yet been used to connect to the other document. Once a hyperlink has been explored, the color of the text and underlining will change to magenta. These default colors are selected by the developer of the web page, so you may find hyperlinks of other colors.
Slide 11: The content of the Internet and the WWW is constantly changing. One of the requirements for a good web site is to keep the material current and changing so your audience will have reason to return to the site. The address of each site can remain the same with only the content of the material that is changed on a continual basis.
Slide 12: The URL is the addressing system for the WWW. Each device (including computers) on a network has a unique IP address (Internet Protocol address). An IP address is a unique, 32-bit numeric address that identifies a specific device written as a 4-part number, each part must be a number between 0 – 255, separated by periods (for example: 127.230.2.112 ). A Domain Name Address is an easier to remember text name that identifies one or more IP addresses. Domain Names are used in the URLs to identify a specific web page. These Domain Names (like usouthal.edu or ) are coordinated by the DNS, which stands for Domain Name Service, which can translate the text name into the correct IP address. The IP address and the Domain Name identify unique computers on the Internet. To access a particular web page, the user must type in the URL into the address bar of the web browser. The URL identifies where the specific web page document resides on the computer. There are 4 specific parts to a URL:
➢ Transfer Protocol (Means of Access) – This is the set of rules that the computer will use to move the files from one computer to another. On a web page this will typically be HTTP or HTTPS.
➢ Domain Name of the Computer (Internet Address)
➢ Pathname to the file on the host computer
➢ File Name of the web page document
Slide 13: Domain names are controlled through the DNS. They are assigned based on the type of web pages that will be associated with that web address. Examples of various domain name extensions are shown on this slide – for example: commercial sites typically have a .com extension; educational sites will have a .edu extension. This can be very important when you look at a site because you can often tell the source of the data found at the web site by the web site domain name extension. We will discuss this more next week when we evaluate internet resources.
Slide 14: This slide gives several examples of various URLs. Each of these URLs can be typed into the address bar of a web browser to display the web page. Since the presentation software that you are viewing this presentation through is “web enabled” you can also simply click on these addresses as they are hyperlinks to the sites. Notice that some of them do not contain all 4 parts of the URL. If the data is stored at the root directory of the web server then there will not be a pathname. Also, if you are viewing the Home Page (in this case Home Page means the main web page of a multiple page web site) at a particular web site then you will not have to enter the file name either.
Slide 15: This slide demonstrates how messages, or web pages, travel across the Internet. The path that the message takes is not important, what is important is the address of the recipient, that would be the address of the computer that is trying to display a web page, and the address of the sender, which would be the address of the web server computer that is storing the web page that the recipient wants to display. There are multiple paths that the message can take, and in fact is may take different routes if accessed different times. The URL addressing scheme and TCP/IP protocols are what allows the Internet and WWW to function correctly.
Slide 16: There are several tools available to use when looking for information on the WWW. These include Search Engines, Web Directories, Meta Search Engines, and Clearinghouses. A Search Engine is a specialized web page that finds other web pages by matching a keyword or phrase. A search engine maintains its own database of available web pages and conducts the search only through its database. Examples of a search engine are Google, Alt Vista, Hot Bot. There will be more information on search engines on the following slides. A Web Directory contains a listing of web pages that are organized into hierarchical categories. Web page developers submit their pages to the Web Directory for inclusion and review. Once the page is reviewed it is put in the directory by category, as determined by people who work for the web directory. Web Directories will also normally contain a hybrid search engine, in that it will search for items first in its directory and then look to the search engine database. It can be difficult to identify exactly which category to look in for the information you need. An example of a Web Directory is Yahoo. Meta Search Engines are search engines of search engines. They combine the power of multiple search engines at one time. They use similar types of programs as search engines to match keywords and search for topics, however, they don’t maintain their own databases, they simply search multiple existing databases. This will give a wide variation in the number and quality of the matches provided by the different search engines. DogPile is an example of a meta search engine. A Clearinghouse, such are Argus – ) will search resources similar to bibliographies. They can help provide a broad overview or a basic understanding of complex subject areas. For example, if you were to use a search engine to look up Quantum Physics, your search would yield complex papers written on topics in Quantum Physics. If you did not understand what Quantum Physics was, or the terminology used, you would probably not understand many of the matches found by a search engine. However, a clearinghouse will give you resource lists, guides, and other links are various intellectual levels.
Slide 17: Most search engines are similar in how they perform searches, however they all have different databases and specialties. This means that searching and identical keyword on multiple search engines could yield very different results. Search engines are maintained through the use of Spider Programs. These spider programs search the WWW to find new sites and pages to add to its database. Learning how to “best” search the web can be complicated task. Proper use of keywords and Boolean operators (And, Or, Not) can play a very important role in finding what you are looking for. When you enter a keyword, or phrase, into the search engine it will return HITS, or links to documents that matched in the search.
Slide 18: There are several ways to make searching more effective. First, you can use multiple search engines, or a meta search engine. We have already discussed that the different search engines maintain different databases and can even evaluate your search phrases differently. Some search engines will look at multiple words as one complete phrase that must match on the search, where others will see each word separately and will match on any word in the phrase. The use of multiple search engines can greatly impact the diversity of the hits that you receive for your search. Boolean / Logical operators, the use of AND, OR, and NOT, can help limit your search results to more appropriate hits. AND will force the search engine to see multiple words as one unit and search on all words, OR will see the multiple words as separate search criteria, and NOT will exclude a word from your search. For example, searching on “Ford AND Mustang” will return hits only on the Ford Mustang, “Ford OR Mustang” will return hits on either Fords or Mustangs (which would include horses), and “Ford NOT Mustang” will return hits on any Ford except the Mustang. Searching on a category first, as opposed to a specific topic, can be helpful if your topic is ambiguous. Category searching can then lead you to more specific terms for additional searches. Advanced Searches can be very helpful when limiting the topic of your search. Search engines can return millions of hits based on a normal search. If you have specific search criteria, this can be included in an advanced search. Advanced searches allow you to filter your search based on language of web pages, date of web page posting, domain name, etc., as well as the inclusion of the Boolean logic. Wildcard characters can also be used when searching. The * character is an unlimited character wildcard so searching on “export*” will return results on exports, exporter, exporters, exporting, etc. The ? character is a single character wildcard so searching on “export?” will return results on export and exports.
When you locate a web site that you would like to revisit, the page can be added to the Favorites list, or Bookmarked, so that you can return to the site without having to remember the URL.
Slide 19: This slide gives a listing of the URLs for many of the more popular search engines. Remember that each search engine will search a little differently, maintain its own search engine, and have its own specialty areas. You will need to try searches with several different search engines to decide which one you prefer based on the type and quality of the hits it returns.
Slide 20: You can save many pictures and other graphics files that you find on web site, for use not in violation of copyright protection – see next slide. To save the image, you simply right click the mouse while it is over the picture and select the “Save Picture As” command.
Slide 21: Copyright protection provides legal protection to a written or artistic work (including web sites), giving the author exclusive rights to its use and reproduction. Copyright protection does not protect ideas, systems, fact, or the method of operation. Just because something exists on a web site, and you have the capabilities of copying the data, picture, etc. does not mean that you can legally or ethically do so. Authors may choose to sell or give up part of their copyright protection, but they are not required to do so. Anything that exists on the Internet should be assumed to be copyrighted unless there is a specific exception. Exceptions to copyright protection include Public Domain and Fair Use. Public Domain means that everyone can freely reproduce and distribute the work, the author has given up their right to copyright protection. The Fair Use exclusion is for educational, non-profit purposes, or for the purpose of critical review or commentary that does not violate copyright law. You can use material on the Internet, and WWW, as long as you do not violate the Fair Use exclusion and include proper citations for the original work. Citations can be in the form of Footnotes or Endnotes for any document using non-original information from any other source, including the Internet. Any copying of copyrighted material outside of these exceptions is considered an infringement of copyright, which is illegal – this includes copying computer software or music files. If copying the file, whatever type of file it is, infringes on the owners right and ability to profit from their work, it is a violation of copyright.
Slide 22: One of the major benefits of the WWW has been in the area of business development through E-Commerce. E-commerce allows for “traditional commerce”, which is the exchanging of goods and services, in the environment of the WWW. All of the requirements for commerce exist, they just exist in a new and different way.
Slide 23: The huge explosion in the area of E-commerce is because it offers benefits to both the buyer and the seller. The buyer gets to enjoy shopping at their convenience, whenever they want to and from wherever they want to (with Internet access). It is very quick and easy for the buyer to comparison shop, as well as find out more details about the products without ever leaving their computer – this can be a great savings of time, money, and gas. As for the seller, they get to remain open for business 24 hours a day, 365 days per year. They can also attract customers from all over the world at any given time. They enjoy lower transaction costs, because the sales are handled electronically and they can maintain a “virtual” inventory – that is sell items that they may not have physically on hand. Not having the maintain a complete physical inventory can save the seller a tremendous amount of money.
Slide 24: E-commerce would not be available if there was not a way to ensure security for transactions taking place on the WWW. One way of securing a transaction is to have a secure transaction. This will take place using the protocol of HTTPS instead of HTTP. When using a HTTPS protocol the status bar will display a padlock icon verifying the security of the transaction. Encryption is another tool used for security. Encryption is the process of encoding the data so that if anyone intercepts the information they will not be able to understand it. It is translated / encrypted prior to transmission and decrypted at the receiving machine. Encryption techniques are built into Internet Explorer for use when accessing secure sites.
With the convenience of a web site remembering who you are, what your preferences are, a wish list of items you want, etc. comes a loss of privacy. The data about you is normally maintained through a Cookie. A cookie is a small file that is written to your computer each time you visit a site. Cookies are not by themselves harmful, they do not damage your machine, they just store information about you. The problem arises when multiple sites, not just the one you accessed, can read the information in the cookie files. This allows web sites to learn your preferences based on your actions at other sites, for such tasks as sending banner ads on your web browser or tracking your movement across several web sites. Existing cookies can be deleted from your computer, but you will lose the personal interaction with web sites. Many sites require the use of cookies when visiting the site, therefore, it is not realistic to change the settings on your computer to not allow cookies and still expect the WWW to function normally. In many ways cookies can be considered a necessary evil, you just need to be aware of how and why they work.
Slide 25 and 26: History Folders and Favorites/Bookmarks allow the user to return to previously visited sites without having the remember the URL. The history folder maintains a listing of all sites visited within a particular time period, as specified in your program options, the default is 20 days. The Favorites option allows the user to sites that they would like to return to. These links are permanently stored within the web browser (or until you delete them) and can be organized by name or within folders.
Slide 27: General summary slide of topics covered by the slide show.
................
................
In order to avoid copyright disputes, this page is only a partial summary.
To fulfill the demand for quickly locating and searching documents.
It is intelligent file search solution for home and business.
Related searches
- introduction to computer systems pdf
- introduction to computer studies pdf
- introduction to computer science
- introduction to computer packages pdf
- introduction to computer pdf notes
- introduction to computer science free
- introduction to computer network pdf
- basic introduction to computer programming
- introduction to computer skills pdf
- introduction to computer pdf
- introduction to computer science class
- introduction to computer science course