Namespace is collection class,structs where as a class an entity can be used to define functionalities.

Namespace is a logical grouping of class,interface,etc.It helps in preventing name collision .We can have 2 classes with same name in different namespace.

Name space provide a way to keep one set of name different from another.. Class name declared in one name space does not conflict with name space declared in another...Class is a collection of objects. It can be used to create multiple copies of object.