Thread: C++ ctime library. How is the functions srand(time(0)) and rand() defined?

I don't know if it's the right place to post this kind of question here, so sorry if so.

But I've been wondering about the srand(), time() and rand() functions since they all make sense when generating a random number. I know that rand() counts how many seconds that have past since 1 Januari 1970 but I don't get how they define the function and the variable that have to increase itself every second.

How does this help us with generating random numbers, I see that it works, but I wanna know more deeply about how they've figured this out and how they got it to work until we hit year 2038. But they've solved that too with something like time_t which goes 584 billon years further into the future until it reaches its limit.
If I've heard right.

So how did they create these functions from the beginning is my question?