Advance C Programming IMP Question

1. what is the difference between actual parameter and formal parameter in c?
2. what is the use of union in c?
3. What is global variable? How to use it in function if same name of variable exists in function as a local variable in C?
4. What is the use of typedef in C?

[ 5 marks imp question ]

1. What is nested structure? Explain with an example in C.
2. Define structure. How to access structure members in C? Explain it with proper example.
3. What is the difference between call by value and call by reference? Give example in C.
4. How to calculate address of 2-D array element? Explain row major with example in C.
5. What is Recursive function? Explain with example in C.
6. Create user define function named rev_array() in C that accept an array as argument and display elements of array in reverse.