C++ - struct vs. class

Possible Duplicates:
C/C++ Struct vs Class
What are POD types in C++?

Hi,

In the C++ In a Nutshell book, in chapter 6: classes, unders Access specifiers, mentioned the following:

In a class definition, the default
access for members and base classes is
private. In a struct definition, the
default is public. That is the only
difference between a class and a
struct, although by convention, some
programmers use struct only for POD
classes and use class for all other
classes.

My questions here are:

• Isn't there another difference between classes and structs in that structs don't hold functions and just hold data?


• What are POD classes? And, what is meant by all other classes here? Are there then special classes?

Thanks.