Programming :: Under Which Circumstances A Child Process Creates Another Child Process Using Fork

Consider the following code:

Code:

int main()
{
int i=0;
pid_t pid;
for(i=0;i<2;i++)

[code]....

I get the following output:

Parent: chid_pid=4356 i=0 parent's pid=4355
This is child 4356 i=0
This is child 4357 i=1

[code]....

I can observe instead of two children(as I expect) processes there are three. This is because child process 4356 creates its own child. Why all the messages of the type "This is child X i=Y" are concentrated one under another? How exactly fork works? Is affected by the fact that I have a dual-core processor?