The list styles available in HTML provide a way to organize groups
of information into visually and logically distinct structures. Each list
style type provides its own method of data organization and should be
rendered differently from the other styles (though this is often not the
case.) All of the HTML list structures were introduced in HTML 2.0 when
there were not any alternative cataloging methods for content (such as tables.)
These styles each have common display properties that will generally
stay the same from one browser to another.
Definition List (DL): This list type represents a list of
terms and corresponding definitions.
Ordered List (OL): These are lists where the items
need to be sorted by sequence or order of importance. The values in
the list marking scheme increment with each successive list item
using an familiar sequence (usually 1,2,3,... but other sequencing can be used.)
Unordered List (UL): This list type specifies standard
symbols to use as non-ordered list markers. For each successive list
item, the symbol will remain the same.
These list styles have an intended use, but a distinct and consistent formatting
strategy has never been established for their display in most browsers. They
are usually displayed as one of the other physical list styles.
Menu List (MENU): This style is used for a list
of items typically having one line per item.
Directory List (DIR): This style is used to represent
a list of short items.