Checked exceptions need to be catch otherwise the program won’t compile. Like I/O operations throw checked exceptions. I.e code won't even compile if we don't put the code for 1/O operations in try catch block or we can throw exception up the calling program using throws IOException{

Please note that if we use the throws method(throws IOException ) then the calling program or calling method also need to use this method(throws IOException {) in calling method we need to define the call to this method in try catch block.

Unchecked exceptions - These kind of exceptions don't throw exception at compile time. But they might throw runtime exception i.e when the code is actually run. Like divide by 0 can throw a runtime exception if the number passed to be divided by is 0.