I am a beginner trying to learn programming in C. Please help me understand what this code does and explain it with non-technical words

```c
#include <stdio.h>
int fib(int n) {
    if (n <= 1) return n;
    return fib(n - 1) + fib(n - 2);
}
 
int main() {
    int input;
    scanf("%d", &input);
    printf("%d", fib(input));
    return 0;
}
```
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