What are Building Blocks of XML Documents?

• Elements:
  
• Tags: tags are used to mark up elements.
  
• Attributes: attributes provide extra information about elements.
  
• Entities:
  
• PCDATA: PCDATA means parsed character data between start tags and end tags.
  
• CDATA: CDATA means the text that will not be parsed which is inside a tag. It is the attribute in DTD.