Explain what the , , and tags are and how they are used. What kinds of tables use them most often?

What will be an ideal response?

HTML supports three row groups: one to mark the header rows, another for the body rows, and a third for the footer rows. The syntax to create these three row groups is

table rows


table rows


table rows


where table rows are rows from the Web table. For example, the following code marks two rows as belonging to the table header row group:


KPAF Programs


Time
Program


Order is important. The thead element must appear first, and then the tfoot element, and finally the tbody element. A table can contain only one thead element and one tfoot element, but it can include any number of tbody elements. The reason the table body group appears last, rather than the footer group, is to allow the browser to render the footer before receiving what might be numerous groups of table body rows.
One purpose of row groups is to allow you to create different styles for groups of rows in your table. Any style that you apply to the thead, tbody, or tfoot element is inherited by the rows those elements contain. Row groups also are used for tables in which table body contents are made up of imported data from external data sources such as databases or XML documents. In those situations, a single table can span several Web pages, with different imported content displayed in the table body in each page but with the same table header and table footer bracketing each page of content.