Dreamweaver Info Index

Dreamweaver: A program made by Adobe Inc. and its purpose is to design and post websites onto the internet.
HTML: Also known as Hyper Text Markup Language, its purpose is to design the "bones" of the site such as text, images, forms, flash, ads, javascript, etc... and is composed of tags with values assigned to them.
CSS: Formally known as Cascading Stylesheets; often used in conjunction with HTML, its purpose is to format the design of the website, such as colors, positioning, fonts, etc... There are two types of CSS, internal and external, internal CSS is when the CSS is embedded into the HTML, and is usually discouraged for big websites because it cannot be updated at once. External CSS is when the styles of the website are on a separate document that links to the tags of the HTML. To emphasize the importance on your browser accordingly:

Firefox: On the menu click on View>Page Style>No Style
IE8: On the menu click on Page>Style>No Style
Safari: On the menu click on the gear symbol >preferences>advanced>check how "Develop menu in menu bar" and exit>click on the page symbol>develop>Disable Styles. Re-enable it once your done.
Chrome: Copy and paste the URL:
Opera: Click Menu>Page>Style>And pick any one style to disable.

HTML Tags: Tags that are used to specify what information you're entering so that the Internet Browsers and CSS know how to display it.

A full list of CSS properties: