(Chapter-8)1.Define the term data dictionary. Define metadata.Data dictionary is a data reference that represents the same data itself.Metadata is a set of data that describes and provides information about other data.2. What are the four reasons to compile a comprehensive data dictionary? The four reasons to compile a comprehensive data dictionary are as follows: a. Check the completeness and accuracy of the data flow diagram b. Provide a starting point for developing screens and reportsc.Determine the content of data stored in ed files.Develop logic for the data flow diagram process3. What information is contained in the data repository? The data repository contains information related to the data managed by the system, including data flow diagrams, data archives, etc. It also contains procedural logic and use cases; screen and report design; relationships between data; project requirements and project management information, such as delivery schedules, etc. Overall it contains everything about data flow diagrams that makes a system work better4. What is a structural record? The reason why a structural record must be created is that when the basic elements of the data flow are grouped simultaneously5. Lists the eight specific categories that each data dictionary entry should contain. Briefly provide the definition of each category. The eight specific categories that each entry in the data dictionary should mandatorily contain are the following: a. Item ID: This is optional and may or may not be assigned. b. The name of the element: This is a unique way to name the element in the data dictionary.cA description of the element: Describes what the element is like and what it does.d.The data type: Shows whether... half of the sheet ......used to determine whether the content of the XML document is valid (if you confirm the order and type of data that must be present in the document) or not16. How does a document type definition help ensure that an XML document contains all the necessary elements? Validate the XML document using standard XML tools. The DTD is easier to create if a data dictionary has been completed.17. When should attributes be used in an XML document? The situation in which attributes are used in an XML document is when the #REQUIRED keyword is present. While #IMPLIED means that an attribute is optional18. What does an ID attribute guarantee? The ID attribute ensures that you check and ensure that an ID starts with a letter or underscore and cannot be a number19. What validates an IDREF attribute?IDREF links one element with another which is usually called an ID