An external CSS is one that is written outside of the HTML document. This is the best was to use CSS because you can apply the same styles to many pages. This is a big advantage when you are trying to create a uniform design throughout your site. You can also create other CSS for browsers that might show the color differently. The CSS documents are written on a separate sheet. For each tag that is in your HTML document you can add a rule in CSS for it. With over 100 different properties you can add style to your web page that could not be added before. You can change the background of your tag and it will go the entire length of the page. If you do not want the background color to span the entire page then you can add margins to it. The only down side to having external cascading style sheets is you have another file that must be uploaded to your web site.
When you use embedded CSS you are creating rules in the tag of the HTML document after the tags. The advantage to using embedded CSS is that you do not need to keep another document with your web page documents. The disadvantage is that you can’t attach these CSS styles to other HTML documents. This is good if you just want one page to have a different look. If you are creating a uniform look throughout your site embedded style sheets would be a waste of time.
If you want to create an inline CSS you just have to add the rule in between the tag you want to change. For example:
then after the text you would place your closing tag. When you use inline CSS rules other CSS do not work for that tag. This is good if you want your and tags to have a different style than the tag they are inside of. When you use special formatting tags they take on the attributes of the paragraphing tags.