The three common table tags are <table>, <tr> and <td>. Each has very special characterisitics.
This tag starts the whole darn table. You can't have a table without a table tag. This tag not only starts a table, it will be used for attributes, such as width, to determine how wide a table should be.
The <tr> tag moves a table DOWN a page. Although rows stretch horizontally across the screen the more rows you have, the more vertical space the table will take up. All tables have at least one row.
The <td> tag divides a row into seperate compartments. These compartments are called table datas or cells. When a table has multiple rows, cells on top of one another create columns.