Why dereferencing is not needed in this case?

[joseplusplus]

Hello, I'm a little confused about this 2 constructs:

To access the vector object, I have to dereference the pointer to get it. I understand this...

  vector<string> *vec = new vector<string>();
  //OK: requires dereferencing to 
  (*vec).push_back("some string");

However, when I have a pointer to an array of vector<string> type, I don't need to dereference! Why is this?

  vector<string> *pvec = new vector<string>[10];
  pvec[2].push_back("the string"); //OK! no dereference needed
  //ERROR: indirection requires pointer operand
  (*(pvec[2])).push_back("the string"); 

Could somebody please explain to me, what's the difference between the 2 cases?

Thanks in advance!