What are differences among throw, throws, and Throwable?

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• In Java, all error's and execption's class are drieved from java.lang.Throwable class. It is the top of the hierarchy of classes of error and exceptions. Only objects that are instances of this class (or one of its subclasses) are thrown by the Java Virtual Machine or can be thrown by the Java throw statement.

• throws is a post-method modifier and specifies which execptions may be thrown by the method. If they are checked exceptions, the compiler will guarantee the code invoking that method must catch these checked exceptions. 
• throw statement is used to throw an error or exceptions. throw statement requires a single argument: a instance of any subclass of the Throwable class or Throwable class. Executing throw statement triggers the JVM to throw this exception and causes an exception to occur.