what is difference between class and void. some other declaration s?

Answer 1

void is basically a function, while class is like a structure but with added tweaks

Answer 2

void is a keyword in c , CPP
it means nothing or no type.
void can be used as FUNCTION ARGUMENT, FUNCTION RETURN TYPE ,AND DATA POINTER.

whereas class is a user define data type, it is the place where object related behavior ,attributes are define. object is variable of class data type.