‘A document may be well-formed but not valid.’ Explain this statement.

Q4. ‘A document may be well-formed but not valid.’ Explain this statement.

Ans. In XML, a document is said to be well-formed if it follows XML guidelines and uses descriptive tags. In other words, an XML document is considered well-formed if all the tags follow XML guidelines and are in their proper places in the document. The following guidelines help in creating a well-formed XML document:

• The document must contain at least one element
• Must have a root element
• Elements must contain the opening and closing tags
• Document must follow the correct tag order
• XML tags must be case-sensitive
• The values of the attributes must be in double quotes

On the other hand, a valid XML document is not only a well-formed document but also one that conforms to the DTD rules.

These rules help define the structure of XML documents with a list of valid elements.