Computing Workshop

www.RockCreekComputing.com

Bill McArthur

Session 4

Topic 1: Internet Browsing

The most popular use of the Internet is visiting web pages using a web browser, for example: Internet Explorer, Mozilla Firefox, Opera, Safari. Each browser has a "home page", which you can modify, where it begins each time it starts up. There is also usually a "home" button which returns to the start page.

A "web site" is a top level web page that is usually specified as a domain name preceded by "www.". For example, you can type "www.rockcreekcomputing.com" into the address line on a browser to reach the materials for this workshop. Note that the "official" name of the web site is

http://www.rockcreekcomputing.com/

You can think of a web site as a folder which contains sub-folders and files. The address of a web page is known as a URL. The address of a web page has a similar appearance to the path name we discussed in Workshop 1. For example: on my Windows laptop, I have a file with path

C:\data\capemaybeachnet\Hawaii2005\cathy8.jpg

This corresponds to the file on the Internet with URL

http://www.capemaybeach.net/Hawaii2005/cathy8.jpg

Note: the portion of the URL after ".net/" IS case-sensitive. If you try any of the following, it will fail to find it

http://www.capemaybeach.net/hawaii2005/cathy8.jpg

http://www.capemaybeach.net/Hawaii2005/Cathy8.jpg

http://www.capemaybeach.net/Hawaii2005/cathy8.JPG

However, the portion of the URL which is the domain name is NOT case-sensitive, so the following URL is VALID:

http://www.CapeMayBeach.net/Hawaii2005/cathy8.jpg

Topic 2: Tabs, Bookmarks, and Favorites

The common browsers all use the "tab" concept. They can present several web pages at once using different tabs. There is normally a small empty tab to the right of the other tabs which, when clicked, creates a new tab. This is handy if you want to go back and forth among different web pages easily. Click here for an example of three tabs in Mozilla Firefox.

You can get your browser to remember web pages by using "bookmarks", sometimes called "favorites." When you are viewing a particular web page, you can "bookmark" the page. Later, you can go to your list of bookmarks or favorites to restore that web page. Click here for a look at some of my bookmarks in Mozilla Firefox. Click here for a look at some of my favorites in Internet Explorer.

Topic 3: Cookies

It is to your advantage to have certain web sites "remember" you and some things about you. For example, when I browse to the Weather Underground web site, it knows that I am a member (for $5 a year) and so doesn't display ads. It also remembers some of the locations that I have recently checked the weather. The way that web sites can remember you is through a small database called a "cookie." Click here for more than you want (or need) to know about cookies. I'm known on Amazon.com, NYTimes.com, Twitter, FaceBook, Active.com, and many other web sites where I pay our monthly bills.

Topic 4: Internet Search

One of the most competitive areas of the Internet is among the various "search engines", such as Google, Yahoo, Ask, Bing, and Alta Vista. Search engines help you to find things that you are looking for, but they also try to direct you toward their customers who pay them for more exposure during searches. Google is the cream of the crop and has even become a verb in the English language.

Effective searching is an art learned through practice. For example, suppose I'm interested in knowing when Angelina Jolie was born. I would Google,

"Angelina Jolie" birthday

The use of quotes groups words for more specific searching. One of the modern ages most egotistical things to do is to Google oneself. For me, this is a problem because of the astronaut Bill McArthur, who is a bit more famous than I am. I can find out about myself by Googling

"William G. McArthur"

When I did that while composing this handout, I discovered that my resume needs some touching up (which I did). Here's a very bizarre thing: try Googling "formal invitation" (without the quotes). At the time that I prepared this handout, the search produced a photo of an invitation to our 40th Anniversary Party, organized as a surprise by our kids.

Topic 5: URL Parameters

Often you will see a complex web address such as:

http://www.wunderground.com/radar/radblast.asp?ID=AMX&region=d5&lat=26.14519&lon=-81.77000&label=Naples%2c%20FL

This particular address has the latitude and longitude of one of our previous campsites in Rock Creek so that we can view real-time radar to see how close we are to dangerous T-storm cells. The "?" separates the name of the web page from the parameters, which are separated by "&". Each parameter is a name/value pair such as "lat=26.14519". Any punctuation in the parameter values is given an ASCII code representation prefixed by "%". For example, a comma is represented as "%2c" and a space as "%20". Here is an ASCII chart. The codes in the parameters can be found in the "Hx" (hexadecimal) column of the table.

Topic 6: Anchors

Some web pages have various points within that can be seperately addressed, called "anchors". The character "#" is used to prefix an anchor, as in the address:

http://www.rockcreekcomputing.com/QuestionsAndAnswers.html#query

In this page, the anchor "query" is used to quickly skip to the form at the bottom of an ever-growing page.

Topic 7: What is a Web Page?

A web page is a text file written in the HTML (HyperText Markup Language) language. Here is a simple example:

<html>
<head>
<title>A Simple Web Page</title>
</head>
<body>
This is a very simple web page isn't it?
</body>
</html>

You can view this web page here. HTML has been generalized into XML (Extended Markup Language) which is the underlying form of many computer documents.