CSCI 121 - Lecture 2 - HTML Essentials

Instructor's Class Notes

1. History of the World Wide Web
1. 25 years old (see CNET article).
2. Proposed by Tim Bernards-Lee, CERN Switzerland, in 1990.
3. The Internet was made public on August 23rd, 1991.
4. First web page of the WWW is still publised at it's same URL http://info.cern.ch/hypertext/WWW/TheProject.html
2. Introduction to HTML
• HTML is a markup language for describing web documents (web pages). HTML stands for Hyper Text Markup Language. A markup language is a set of markup tags. HTML documents are described by HTML tags. Each HTML tag describes different document content.*
• Excellent resource: http://www.w3schools.com/
• HTML tag - the first tag of an HTML document
• HEAD tag - typically the second tag of an HTML document, can hold any of the following tags
• TITLE - required in an HTML document
• defines a title in the browser toolbar
• provides a title for the page when it is added to favorites
• displays a title for the page in search-engine results
• STYLE - The style tag is used to define style information for an HTML document.
• Inside the style element you specify how HTML elements should render in a browser.
• Each HTML document can contain multiple style tags.
• More discussion on STYLE and styles when we cover Cascading Style Sheets (CSS).
• BASE - The base tag specifies the base URL/target for all relative URLs in a document.
• LINK - Link to an external style sheet or other external resource file.
• META - The meta tag tag provides metadata about the HTML document. Metadata will not be displayed on the page, but will be machine parsable.
• Meta elements are typically used to specify page description, keywords, author of the document, last modified, and other metadata.
• The metadata can be used by browsers (how to display content or reload page), search engines (keywords), or other web services.
• SCRIPT - The script tag is used to define a client-side script (JavaScript).
• The script element either contains scripting statements, or it points to an external script file through the src attribute.
• Common uses for JavaScript are image manipulation, form validation, and dynamic changes of content.
• NOSCRIPT - The noscript tag defines an alternate content for users that have disabled scripts in their browser or have a browser that doesn't support script.
• The noscript element can be used in both head and body.
• When used inside the head element: noscript must contain only link, style, and meta elements.
• The content inside the noscript element will be displayed if scripts are not supported, or are disabled in the user's browser.
• BODY - The body tag defines the document's body.
• The body element contains all the contents of an HTML document, such as text, hyperlinks, images, tables, lists, etc.

* from w3school.com