What is symbolic constant in C?

#include <stdio.h>
    #define PI 3.14
    #define MAX_VALUE 100
    int main() {
        float radius = 6.0;
        float area = PI * radius * radius;
        printf("The area of the circle is: %f", area);
        printf("\n");
        int number = 75;
        if (number < MAX_VALUE) {
            printf("The number is less than the maximum value");
        }
        return 0;
    }
    

The area of the circle is: 113.040001
    The number is less than the maximum value