title: Do I have to use #include <string> beside <iostream>?
body: <p>I started learning C++ and I read a book which writes that I must use the <code>&lt;string&gt;</code> header file because the string type is not built directly into the compiler.
  If I use the <code>&lt;iostream&gt;</code> I can use the string type.</p>
  
  <p>Do I have to include the <code>&lt;string&gt;</code> header when I want to use the string type if I included the <code>&lt;iostream&gt;</code> header? Why? Is there some difference?</p>