W3C CSS2 Cascading Style Sheets, level 2 - instructional media + ...

cells
rows
row groups
columns
column groups
table
Schema of table layers.
1. The lowest layer is a single plane, representing the table box itself. Like all
boxes, it may be transparent.
2. The next layer contains the column groups. The columns groups are as tall
as the table, but they need not cover the whole table horizontally.
3. On top of the column groups are the areas representing the column boxes.
Like column groups, columns are as tall as the table, but need not cover the
whole table horizontally.
4. Next is the layer containing the row groups. Each row group is as wide as
the table. Together, the row groups completely cover the table from top to
bottom.
5. The next to last layer contains the rows. The rows also cover the whole
table.
6. The topmost layer contains the cells themselves. As the figure shows,
although all rows contain the same number of cells, not every cell may have
specified content. These "empty" cells are transparent, letting lower layers
shine through.
In the following example, the first row contains four cells, but the second row
contains no cells, and thus the table background shines through, except where a
cell from the first row spans into this row. The following HTML code and style
rules
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