Hi Manish,
In short - these are Vendor specific!!!
In detail, for
EJB Home - Most containers will have a 1:N relationship between home objects and bean instances.
EJB Object - Some containers can have a 1:N relationship, where each EJB Object is multithreaded. Other containers might have M:N relation ship, where M represents the number of EJB objects instantiated. In this case, each EBJ Object is single threaded.
So most containers will have one Home Object and one EJB Object.
If you can go through 'Mastering EJB II' @
www.theserverside.com chapter 2, you will get a clear Idea.
Cheers
~KK