Answer :
The advantages of External Style Sheets are:
1. Using them, the styles of multiple documents can be controlled from one file.
2. Classes can be created for use on multiple HTML element types in many documents.
3. In complex situations, selector and grouping methods can be used to apply styles.
The disadvantages of External Style Sheets are:
– In order to import style information for each document, an extra download is needed.
– Until the external style sheet is loaded, it may not be possible to render the document.
– For small number of style definitions, it is not viable.