A variable in C programming is a named storage location that holds a value of a particular data type. It allows the programmer to store and manipulate data during the execution of a program.

To create a variable in C programming, you must specify its data type and name. Here is an example of declaring a variable of integer type named num:

int num;

This statement declares a variable of integer type named num, but it does not initialize its value. To initialize a variable, you can assign a value to it using the assignment operator (=) as shown below:

num = 10;

You can also declare and initialize a variable in a single statement as shown below:

int num = 10;

It is important to note that variables in C are case-sensitive. That means num and Num are two different variables.

Once a variable is declared, you can use its name in expressions and statements to access its value or to assign a new value to it. Here are some examples of using a variable in C programming:

int num = 10; // declare and initialize a variable
num = num + 5; // add 5 to the value of num
printf("The value of num is %d", num); // print the value of num

In this example, we declared and initialized a variable named num with a value of 10. We then added 5 to the value of num using the + operator, and printed its value using the printf function.

It is good programming practice to initialize a variable when it is declared. Uninitialized variables can lead to unpredictable behavior in your program.

In summary, a variable in C programming is a named storage location that holds a value of a particular data type. To create a variable, you must specify its data type and name. Once a variable is declared, you can use its name in expressions and statements to access its value or to assign a new value to it.