150 likes | 326 Views
How the World Wide Web Works. What Is the Web?. The World Wide Web is a collection of electronic documents linked together like a spider web. These documents are stored on computers called servers located around the world.
E N D
What Is the Web? • The World Wide Web is a collection of electronic documents linked together like a spider web. • These documents are stored on computers called servers located around the world. • The Web has evolved into a global electronic publishing and commerce medium.
What Is the Web Made of? • The Web consists of: • Your personal computer or mobile device • Web browser software to access the Web • A connection to an Internet service provider (ISP) • Servers to host the data • Routers and switches to direct the flow of data
How the Web Works • Web pages are stored on web servers located around the globe. • Entering the Uniform Resource Locator or URL of a web page in your web browser or clicking a link sends a request to the server that hosts the page. • The server transmits the web page data to your computer/device and your web browser displays it on your screen.
Web Pages • A web page is an electronic document written in a computer language called HTML (Hypertext Markup Language). • Web pages can contain text, graphics, audio, video, and animation, as well as interactive features, such as data entry forms and games. • Each page has a unique address known as a URL (Uniform Resource Locator), which identifies its location on the server. • Web pages usually contain hyperlinks to other web pages. Hyperlinks are text and images that reference the addresses of other web pages.
Websites • A website consists of one or more web pages that relate to a common theme, such as a person, business, organization, or a subject, such as news or sports. • The first page is called the home page, which acts like an index, indicating the content on the site. For this reason, its file name is typically index.html • From the home page, you can click links to access other pages on the site or other resources on the Web.
Navigating the Web • There are three main ways to move between web pages or websites: • Clicking a text link. • Clicking a hyperlinked graphic, such as a button, photograph, or drawing. • Typing the URL of a web page in the location box (also known as the address field) of your web browser and then pressing the Enter or Return key.
Identifying a Hyperlink • Text links are usually underlined and in a different color from the rest of the text. • To determine if a graphic is hyperlinked, move your cursor arrow over the image. You know the item is hyperlinked if: • The arrow turns into a hand. [Hand Icon] • A URL appears in the status bar at the bottom of your web browser (except in some browsers such as Safari.)
How Hyperlinks Work • A text or graphic hyperlink hides a URL. • Clicking a hyperlink passes the URL to your browser. • The text or image you click on is called the label. • In addition to pointing to web pages, hyperlinks can access media files or pop open photo viewing windows.
Using Web URLs • A URL indicates where the web page is stored on the Internet. • URLs never use back slashes (\). All slashes are forward slashes (/). • You need to type a URL exactly for your browser to locate the desired web page. Otherwise you will access the wrong site or get an error message. • URLs may not contain spaces between characters. • The location box or address field on your browser indicates the URL of the page you arrived at after clicking a link.
Examples of URLs • http://www.learnthenet.comThe home page for the Learn the Net website. • http://blog.wired.com/Blogs or weblogs from Wired magazine. • ftp://rtfm.mit.edu/pub/A directory of files at the Massachusetts Institute of Technology (MIT) that you can download. • news:rec.gardens.rosesA newsgroup about rose gardening.
Anatomy of a URL • Here's how to interpret the various parts of a URL: http://urlnextdoor.com/ai/web-design_1-fundamentals/index.php • http://Short for Hypertext Transfer Protocol, this indicates a Web document or directory. • www.This indicates a page on the World Wide Web. (These days, the "www" is usually optional, which is why its not used for the URL above.) • urlnextdoor.comThis is the domain name, which includes the top-level domain (below). • .comCalled the top-level domain, it often indicates the name of a company, university, or organization. It can also tell you the country of origin. • /Forward slashes separate parts of the file structure. • ai/and web-design_1-fundamentals/These are the folders on the web server that contains groups of related web pages within the website. • index.phpThis is a web page inside a folder. A URL doesn't always include the file name of the web page. In this case, using http://urlnextdoor.com/ai/web-design_1-fundamentals/ would have worked just as well., because index.php is the default page for the folder.
Saving an Image from the Web • Place your cursor over the graphic you want to save. • Windows users: Click the right mouse button. A pop-up box appears. • Macintosh users: Click and hold the mouse button. A pop-up box appears. • Save the image to your hard drive by selecting a Save Image As… or similar option. • You can accept the current file name or rename the file (web graphic files are usually in .gif, .pngor .jpg formats—don’t change this file extension!)