title: Libraries vs classes in c++
body: <p>I came across a terminology in C++ which is a library. The book I am reading states that iostream is a library , and it is a system library. Then After that it says in the book, "later, you will create your own library with the extension .h". Is a library the same as class because clearly, when I included my .h library, I actually had created a class. 
  If a library is the same as a class, what can we say about  in C language , is it a class ? 
  Thank you. </p>