What is The main use of structures

The main use of structures is to lump together collections of disparate variable types, so they can conveniently be treated as a unit. For example, if we were writing a student record we might need for each identifier information like his name (a character array), his reg.no (an integer), and his address ( a character array).

i.e.

char name[15];

int regno;

char address[40];

We can make a structure out of this quite easily.  We first tell C what the structure will look like, that is, what kinds of things it contains; after that we can actually reserve storage for it, either in the same statement or separately.  The simplest thing is to define it and allocate storage all at once:

struct stud{

 student;

char name[15];

int regno;

char address