XHTML stands for eXtensible Hypertext Markup Language, and is basically
HTML 4.0 with stricter rules. For clarification during this course,
concepts that are the same in both HTML and XHTML will be referred to
as HTML, whereas concepts that are unique to XHTML will be referred to as
XHTML.
In most cases, HTML and XHTML are the same, and it is our goal to create
code that is compatible with both. When differences between the two
occur, we will discuss how they are different and how to ensure our code
is compatible with both.
The most important restriction is that all XHTML tags must be in lowercase,
whereas HTML tags are not case sensitive.
