What is the purpose of Standard Generalized Markup Language (SGML)?

The purpose of Standard Generalized Markup Language (SGML) is that it serves as a metalanguage used to create other markup languages, such as HTML and XML. SGML provides a framework that defines rules for how documents should be structured and represented, helping to ensure that the content is both machine-readable and human-readable. This flexibility allows developers to define their own markup elements and attributes according to the needs of their specific applications, making SGML a foundational standard in the development of markup languages.

The significance of this metalanguage lies in its ability to accommodate a wide variety of document types and structures without being limited to a single format. By establishing a set of generic rules, SGML laid the groundwork for more specialized languages that followed, including HTML (HyperText Markup Language) for web pages and XML (eXtensible Markup Language) for data interchange.

In contrast, the other options focus on unrelated aspects of technology; they do not pertain to the primary function of SGML as a standard for markup language creation. For instance, security protocols and graphic creation are entirely different domains, as is the management of database relationships, which does not connect with SGML's core purpose.