Question

Why do we at all use integers in C?

#include<stdio.h>
int main()
{
    char c=10;
    printf("%d",c);
    return 0;
}

Is same as:

#include<stdio.h>
int main()
{
    int c=10;
    printf("%d",c);
    return 0;

}

Answer 1

Technically all datatypes are represented with 0’s and 1’s. So, if they are all the same in the back end, why do we need different types?

Well, a type is a combination of data, and the operations you can perform on the data.

We have ints for representing numbers. They have operations like + for computing the sum of two numbers, or - to compute the difference.

When you think of a character, in the usual sense, it represents one letter or symbol in a human readable format. Being able to sum 'A' + 'h' doesn’t make sense. (Even though c lets you do it.)

So, we have different types in different languages to make programming easier. They essentially encapsulate data and the functions/operations that are legal to perform on them.

Wikipedia has a good article on Type Systems.