headerCell

headerCell is a term used in data tables and grids to denote a cell in the header row that labels a column of data. It appears in the topmost row of a table or in the header section of a grid, and its primary role is to convey the meaning of the column to users and assistive technologies. In HTML, the header cell is typically implemented with the th element inside the thead element. The th element can carry scope attributes such as scope="col" to indicate that the header applies to a column, and it can include aria attributes, such as aria-sort, to reflect the current sort state.

In user interface libraries, headerCell objects or components render the column labels and often provide interactivity, such as sorting, filtering, or resizing. They may support keyboard focus, allowing users to activate sort or other actions with Enter or Space, and may include visually distinct styling (bold text, background color) and resizable gutters.

Accessibility considerations are central for header cells. Proper use of semantic elements and ARIA attributes helps screen readers announce the correct relationship between header cells and data cells. For grids with complex headers, header cells can be grouped with scope values like col and colgroup, and announced by assistive technologies through aria-label and descriptive text.

See also: th element, table header, column header, data grid, accessibility in tables.