In structured documentation, the purpose of links and references is to provide a connected and organized information ecosystem, allowing users to navigate and access relevant content efficiently. These links and references play a crucial role in enhancing the user experience and the usability of documentation. Here are the key purposes of links and references in structured documentation:

1. Cross-References: Cross-references enable users to navigate between different sections or topics within the documentation. They serve as signposts, guiding readers to related content that provides context or additional information. In DITA, cross-references are implemented as follows:

<!-- Example: DITA Cross-Reference -->
<ph><xref href="related_topic.dita"/></ph>

2. Definitions and Terminology: References to key definitions and terminology ensure that users have access to clear and concise explanations of important terms. This is often achieved through key references in DITA, helping users understand the specific terminology used within the documentation:

<!-- Example: DITA Key Reference -->
<term keyref="term_definition_key">Key Term</term>

3. External Resources: Links to external resources such as websites, documents, or online references provide users with opportunities to explore additional information beyond the structured documentation. These links can connect users to authoritative sources or supplementary materials:

<!-- Example: DITA External Link -->
<ph><xref href="https://www.example.com"/></ph>

By integrating links and references effectively, structured documentation becomes a valuable tool for conveying information, fostering understanding, and ensuring that users can navigate through the content with ease.