Why does C++ have both classes and structs? [duplicate]

Question

Possible Duplicate:
What are the differences between struct and class in C++

If the only difference between structs and classes is the default access specifier(in C++), then why does C++ also have classes?

Answer 1

First, it's backward compatibility with C. Second (and more importantly), it helps describe your intent. The standard convention is that PODs should be denoted with struct and collections of data and behavior should be denoted with class.