Describe the four basic symbols of

Describe the four basic symbols of
Gane and Sarson symbol set.Describe a data dictionary and list the types of information it contains.What is a decision tree and how it is used ?Define encapsulation, and explain how it is used in object-oriented analysis.Define the term “black box”, and explain why it is an important concept in object-oriented analysis. Can you think of other black boxes that you use in everyday life?