What is SGML in XML?
SGML descended from IBM's Generalized Markup Language (GML), which Charles Goldfarb, Edward Mosher, and Raymond Lorie developed in the 1960s. Goldfarb, an editor of the international standard, coined the "GML" term using their surname initials. Goldfarb also wrote the definitive work on SGML syntax in "The SGML Handbook".
HTML and XML are both descendants of an earlier markup language called SGML (Standard Generalized Markup Language). SGML is a complicated set of rules that define document structures. XML is a subset of SGML that does the same thing, using fewer rules. XML delivers the power of SGML without the complexity.
SGML is used for marking up documents and has the advantage of not being dependent on a specific application. It is derived from GML (generalized markup language), which allowed users to work on standardized formatting styles for electronic documents.
Which is used to define descriptions of the structure of different types of an electronic documents?
What are rules for well formed XML document?
Which one describes how to display an XML document for a given type?
Which are used to avoid element name conflicts in XML?