What benefits and demerits do External Style Sheets have?

The advantages of External Style sheets are:

• The style of several documents can be controlled from site by using them.
• Multiple HTML elements can have many documents, where classes can be created.
• To group styles in complex situations, selector and grouping methods are used.

Demerits of external css are as follows:

• Extra download is needed to import documents having style information.
• To render the document, the external style sheet should be loaded.
• Not practical for small style definitions.