In DITA, the <entry> element is a fundamental component of tables used to represent individual data cells within a table. It plays a crucial role in structuring and organizing tabular data.

The primary purpose of the <entry> element is to define individual cells within a table. It represents the data contained in a specific cell and is essential for creating structured, organized tables.

The <entry> element can contain various types of content, such as text, numbers, links, inline elements, and even nested tables. This flexibility allows for presenting diverse data within a single cell.

<entry> elements can include attributes that provide additional information about the cell, such as its alignment (align attribute) and data format (format attribute).

Example:

This simple table in DITA illustrates the use of the <entry> element:

<table>
  <title>Sample Table</title>
  <tgroup cols="3">
    <thead>
      <row>
        <entry>Item</entry>
        <entry>Description</entry>
        <entry>Quantity</entry>
      </row>
    </thead>
    <tbody>
      <row>
        <entry>Product A</entry>
        <entry>High-quality product</entry>
        <entry>10</entry>
      </row>
      <row>
        <entry>Product B</entry>
        <entry>Advanced features</entry>
        <entry>5</entry>
      </row>
    </tbody>
  </tgroup>
</table>

In this example, each <entry> element represents a cell within the table. The first <entry> in the <thead> denotes the column headers, while the subsequent <entry> elements in the <tbody> contain data for each cell.