A table row runs horizontally in a line across a table and is normally made up of several boxes with information inside. When you draw a table on a piece of paper, you are creating columns and rows. Each horizontal line of boxes is a different table row. Often, the row at the top of the table is used to create headers, which tell the reader what information can be found in the boxes below it, also known as the column. For example, the first three boxes in the first row of a table in a teacher’s attendance book might read "Student's Name," "Present," and "Absent."
Table rows are commonly used in HTML to create tables and to format a web page. The HTML tag for a table row is <tr>. Within each row, the tag <td> must be added for each new box the user wants to create in that row. A new table row must be created to move down to the next line and start a set of boxes below the first. This example shows a table with three table rows and three table columns.
In the past, many web designers used hidden tables to layout their website. They could make the table invisible and put everything from the text to the images in its own separate part of the table. This kept things from moving around or overlapping. While it's still possible to use tables to design a web page, it is quickly being replaced by the use of CSS to format a page's layout.
Table rows can contain boxes of different lengths than the row before or after it. One table row might only have two boxes, one large and one small, while the row below it has three small boxes. The rows should still be the same length total, but the boxes may not match.
Programs like Microsoft Excel use rows and columns to create spreadsheets. Often, the user will alter the length of the boxes in a row to give himself room to type in the necessary headings. When changing the length of a box, it changes the length of the entire column below it to keep it aligned. Users also have the option to merge rows vertically, causing one box to take up more than one line and giving more room for information. This does not alter any other boxes on the screen.