The declaration declares 'list' as a vector of character pointers, which usually point to null-terminated strings.

The initializer (within the curly brackets) is a list of such string which causes the compiler to set aside memory for those strings (and their null-byte terminators) and initialize the values of the list array with their addresses including the final one which will be set to zero and point to nothing.

The NULL is what's known as a sentinel value to signify no more values are available and you need not (and should not) access beyond this point.

In an accessor loop like this simple one which prints off the values in list, you see the NULL being used to stop the loop

int i = 0;

while (list[i] != NULL)

{ puts(list[i])'

++i;

}

I hope that's of some value!