Information for Cascading and inheritance !!!!!

The final style for an element can be specified in many different places, which can interact in a complex way. This complex interaction makes CSS powerful, but it can also make it confusing and difficult to debug.
Three main sources of style information form a cascade. They are:
• The browser's default styles for the markup language.
• Styles specified by a user who is reading the document.
• The styles linked to the document by its author. These can be specified in three places:
o In an external file: this tutorial primarily discusses this method of defining styles.
o In a definition at the beginning of the document: use this method only for styles that are used only on that page.
o On a specific element in the body of the document: this is the least maintainable method, but can be used for testing.