Document Type Defination is used to validate XML Document that Valid XML document  must be well formed (satisfy all the basic syntax condition).DTD defines the  structure of the XML document and a list of legal elements of the XML document.The DTD, whether included as part of the XML file or external to the XML file is used to define content. It is used to determine the elements allowed in the file and which elements can be contained in other elements. 
                  
                  
                  
                    
Step 1:
 Create .xml document 
                  Step 2:
 Create .dtd file
                  Step 3:
 Link .dtd file to .xml document 
                  Step 4:
 Use following command on terminal for validate xml document 
                  
                  Execution Command:
                     
                  "xlint valid "
                   
                                            
                  
                  
                  
                  | Topic | View/Download | 
                  
                  | Document Type Defination | View |