When programming, sometimes you need to store different kinds of related data together. For example, an employee's file might include their name, age, work hours, and salary. Instead of having many separate variables, we need a way to group these related pieces of information together in an organized manner.

Arrays let us store multiple items of the same type, like a list of numbers or characters. But they can't handle storing different types of data together, like an employee's details.

This is where Structures come in. A Structure is a user-defined data type in C that lets you combine different types of data in one place. Each piece of data in a structure is called a member. For instance, an employee structure could have members for name, age, work hours, and salary. Structures are great for creating databases because they can hold various kinds of related information together.

Similar to structures, there's another user-defined data type called a Union. Unions also store different types of data, but they do so in a way that only one type of data can be stored at a time.

Objective

1. declare and initialize the members of the structures;
2. access the members of the structures;
3. pass the structures as function arguments;
4. declare the array of structures;
5. declare and define union; and
6. perform all operations on the variables of type Union.