Most browsers that can display tables allow control over the size and spacing of data cells, border thickness and color, and other attributes. Also, most other kinds of HTML tags also function within data cells, giving you a wealth of ways to display your data and information. The indentation of the lines of code is arbitrary and for clarity in reading the code. Each pair represents one cell, containing either a header or data respectively. Thus, in our example there is one header cell plus two rows of data cells each comprised of two cells.
Headers automatically appear in boldface.
Header and data cells are automatically sized to accomodate the longest data element in a column. These control the amount of space between cells and within cells respectively. The first controls the alignment of data within each cell in the row. The second controls the vertical alignment of data within each cell in a row. They function identically except that headers are usually rendered in boldface type.