<th>
A header cell that other cells reference for meaning.
Baseline: Widely available · Tables
When to use it
Always with scope (col or row); in irregular tables give each th an id and point data cells at them with headers.
When not to
A th without scope leaves screen readers guessing which cells it governs.
Key attributes
scope- col | row | colgroup | rowgroup
id- target for headers associations
colspan / rowspan
Example
<tr>
<th scope='col'>Region</th>
<th scope='col'>Revenue</th>
</tr>