CS117 Introduction to Computer Science II Lecture 1 Introduction to WWW and HTML Instructor: Li Ma Office: NBC 126 Phone: (713) Webpage: Department of Computer Science Texas Southern University, Houston January, 2011
Hardware and Software required An IBM or compatible computer with –A Pentium processor –16 MB of RAM –A Windows 98 or higher operating system A Macintosh computer with –Similar memory, color, graphics, and video capacities
Hardware and Software required (cont’) A text editor program such as Notepad A Web browser –Internet Explorer or Navigator Access to Internet An external media storage device Some type of graphics-editing software An FTP client software program
Preparation for the Class in the Lab Set up your Itcs account Data files –There are two ways to get the data package From the Web site From the Itcs server Save all your jobs on Z:/ drive –Create a folder for each topic For example, a folder cs117 for this class
Web Concepts World Wide Web (WWW) is information contained on Internet Internet is the vast network of interconnected computers Web sites are related collections of files stored on the computers on Internet –Web pages: HTML text files –Images or other files like digital video
Web Concepts (cont’) A Web browser is a software program that allows you to view Web pages Hyperlinks are specially-formatted text or graphics user click to move from one file to another on the Web A uniform resource locator (URL) is the exact Internet address of a Web file A search engine is a Web-based program that helps you locate information on the Web
What is HTML? Hypertext Markup Language (HTML) is a standard language used for all pages on the World Wide Web It allows various computer systems to interpret the information on the Web in the same way The suffix of the domain name specifies the type of organization to which the computer belongs A Web page is simply a text file made up of text and HTML instructions
What is HTML? (cont’) HTML can describe: –The display and format of text –The display of graphics –Pointers to other html files –Pointers to files containing graphics, digitized video and sound –Forms that capture information from the viewer
What is HTML? (cont’) HTML was developed by Tim Berners-Lee of CERN around 1990 HTML is understood by the WWW browsers that will interpret and display the output to the viewer –Microsoft’s Internet Explorer –Netscape’s Navigator
Browsers Are Tolerant Browsers follow the rule of being tolerant of mistakes in the input –They ignore markup they don’t understand Netscape Navigator/Microsoft Internet Explorer are tolerant browsers –They do not insist that the HTML document begin with and end with – and/or tags are not required –But, there is no guarantee that this behavior will be the same for all browsers
World Wide Web Consortium World Wide Web Consortium (W3C) is an independent industry consortium –develops common protocols and sets new standards for WWW –promotes WWW evolution and ensures interoperability among products and platforms
W3C Coding Standards Use lowercase letters –DHTML and XML are case sensitive Tag sets –a pair of opening tag and closing tag, or –only an opening tag with a single space and a closing slash (/) after the tag name No spaces in folders or file names Keep it neat Put everything in its place: for stacked tags or nested tags
General Structure A leading line indicates which version of HTML this document conforms to <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" " HTML documents for Web pages have a head and body –head should contain a title –body may have paragraphs
General Structure (cont’) The Solar System The nine planets of the solar system are...
HTML Elements and Tags Some elements consist of an open tag, content, and a closing tag –e.g. some text –A slash after the “<“ indicates a closing tag Some elements do not require closing tags –e.g. Some elements do not require content –e.g. and
Comments in HTML Comments start with Comments cannot be nested –White space is permitted between the -- and the closing angle bracket –It is not permitted between the opening angle bracket, exclamation point, and the -- For example: But this will be displayed