Difference between NSArray and NSMutableArray in Objective C

      NSArray is Immutable and ordered collection i.e you can not update if once its  initialized while

    NSMutableArray  is Mutable and ordered collection  i.e you can add more object as per your requirement     

Example:

    NSArray *arr1 = [[NSArray alloc]initWithObjects:@"Amit",@"Jai",@"Sudheer", nil];

        NSLog(@"%@",arr1);

outPut :

2013-05-02 11:34:43.372 FirstStoryBoardViewController[418:c07] (
    Amit,
    Jai,
    Sudheer
)

[arr1 addObject:@"Kiran"]; if we try to do like this,we get build error as 

    No visible @interface for 'NSArray' declares the selector 'addObject':

   NSMutableArray *Muarr1 = [[NSMutableArray alloc]initWithObjects:@"Amit",@"Jai",@"Sudheer", nil];

  NSLog(@"%@",Muarr1);

outPut :

2013-05-02 11:34:46.226 FirstStoryBoardViewController[418:c07] (

    Amit,

    Jai,

    Sudheer

)

 [Muarr1 addObject:@"Kiran"];

NSLog(@"%@",Muarr1);

 outPut :

  2013-05-02 11:37:37.178 FirstStoryBoardViewController[458:c07] (

    Amit,

    Jai,

    Sudheer,

    Kiran

)