I think the difference betwteen the two is the way the exceptions are handle.
When using "throws" you must create a Exception class that must perform the actions needed when the exception is encountered. Then the function that can throw the exception must be accordingly declared :
public somefunction() throws Exception
And inside the function :
if (exceptionCondition=true)
throw new Exception
When uisng try/catch the actions that msut be performed when the exception is encountered are written inside the function.
try
{
//
}
catch (Exception e)
{
//handling exception...
}