The thead and tfoot elements define header and footer rows for tables. They provide no accessibility functionality and are generally only of use when a long table is printed - the head and/or foot rows will repeat at the top or bottom of each printed page. Similarly, the tbody element defines the body content of a data table (meaning anything that’s not a thead or tfood). Again, this element does not provide any additional accessibility benefit, but there is no harm in using it for table styling or other reasons.