what does ** or *** mean?

what does ** or *** mean?

I would be thankful if anyone can help me about two questions.
First, What does below code mean?
offset[0] = (*iter)->point[0] - (int)((*iter)->point[0]);
what is the difference between these two terms?
(*iter)->point[0] and (int)((*iter)->point[0])
Second, what does two or three pointer sign mean in below code?
myarray = new myStruct***[sizex];
for (i=0; i<sizex; i++) {
myarray[i] = new myStruct**[sizey];
for (j=0; j<sizey; j++) {
myarray[i][j] = new myStruct*[sizez];
}
}