1. final - it is a constant declaration.
2. finally - handles exception. The finally block is optional and gives a mechanism to clean up regardless of what occurs within the try block. Use the finally part to close files or to free other system resources like database statements, connections etc.
3. finalize() - method performs in garbage collection. A method that is called before an object is discarded by the garbage collector, appearing it to clean up its state. Could not be need to release non-memory resources like sockets, file handles, database connections etc because Java has only a fix number of these resources and you do not know when the garbage collection is working to kick in to release these non-memory resources through the finalize() method.