I have some confusion in core data?

I am new in core data please help me in some confusions...

1. 
   

   If core data use sqlite in back end then why we use core data not sqlite??

   
   


2. 
   

   How it is faster then sqlite.

   
   


3. 
   

   I read a difference that In core data when we want to edit anything it loads all data in memory..but if it loads then why app. not getting slow or crash.

   
   


4. 
   

   How to show data of a (.sqlite) file that store in Document Directory.

   
   


5. 
   

   core data is use for persistence storage but it's not a data base.

   
   

Please define all things to me...

Thanks in advance.