A variable in simple terms is a storage place which has some memory allocated to it. Basically, a variable used to store some form of data.
Difference b/w variable declaration and definition
Variable declaration refers to the part where a variable is first declared or introduced before its first use. Variable definition is the part where the variable is assigned a memory location and a value. Most of the times, variable declaration and definition are done together.
#include <stdio.h>
int main()
{
// declaration and definition of variable 'a123'
char a123 = 'a’; // This is also both declaration and definition as 'b' is allocated
float b; // memory and assigned some garbage value.
int _c, _d45, e; // multiple declarations and definitions
printf("%c \n", a123); // Let us print a variable
return 0;
}