Catching or Methods Throwing Exceptions

Question

Hi,
I'm just wondering whats the difference between catching an exception and a method throwing an exception?
I'm a bit confused on their purpose dealing with exceptions.
catching an exception
void p1()
          try{
               p2();
          }catch(IOException ex){
     }method throwing an exception
void p1() throws IOException
          p2();
     }

Answer 1

one more stuff i need to add is that:
When we declare a particular code within a try catch
statement it means that that particular code is very
much prone to an exception , i mean the programeer
knows that code will throw a exception and hence we
mention in try catch block.
But in other case when we suffixed that particular
method with throws clause it means the programmer is
not sure ,that code might throw an exception,hence we
put in throws clause.Not quite, the programmer always knows if a checked exception is being thrown, since the compiler requires it to be caught or having a throws clause. Unchecked (runtime) exceptions don't require a throws clause and the programmer must/can catch it if he wants to.