Answer 1

+ you can throw exception with statement: 'throw' too , for example, if something is unexpectedly wrong and programm can't continue. If exception is throwed you can catch it with statement: 'catch' in other
place of code and then is not necessary to stop program because of there was error.

Answer 2

First understand what compile time erroer and what is runtime erroer.
Compile time erroer : if your programme have any syntax error like forget to put semicolan and missing curly brakets ext.. than compiler throw an erroer.

Runtime erroer : If there is no syntax error in your program.But somthing error like devide any number with 0 than compiler throw an Airthmatic exception it means runtime error.