Behind the scene of a class/Type i.e, How class/type works ?

[kcvinu]

Hi all, This is not a nim specific question. But if you answer it in the nim 
way, i can easily understand. When we declare a class/type what is happening 
behind the scene ? I mean for example, take this code and kindly explain what 
will the compiler do with this code ? If you think some links are better than 
an answer, then please point me. Thanks in advance. 
    
    
    type
        MyClass* = ref object of RootObj
            strVar* : string
            intVar* : int
            seqVar* : seq[string]
    
    
    Run