Java EE (Java Enterprise Edition) General Discussion

1.if any body could expalin me whta is the difference between ejbCreate()
and ejbPostCreate();

2. if i have a 2 create method in the home interface
like
create(int a),
createBigbj(int b);

here in bean class we can declare methods like
ejbCreate(int a)
ejbCreateBigbj(int b);

but how many ejbPostCreate method i should have for these methods