packages were called development classes in the earlier 
version of SAP (from 4.6c onwards developemnet classes are 
packages)

We called development class in the version 4.6 . And that 
we called Package called in the 4.7E VERSION......THERE IS 
NO DIFFERENCE IN BETWEEN THESE 2 ONES ...

Hi,

Development class classifies the objects belonging to the 
same development project.
When a user creates a object in R/3 system, the object 
needs to be stored in particular development class. The 
development class are object themselves. In R/3 system you 
store objects.

In local object i.e., object is stored in $tmp class and 
cannot be transported from one system to another.

User can assign his own development class and can be 
transported.

Package is for the group of objects in the same module or 
similar purpose. development class and package is having 
same meaning.