What is Persistence

When you make an object, it exists for so long as you need it, but under no circumstances object exist when program terminates. While this makes sense at start, there is condition in which it would be incredibly helpful if an object could exist and keep its information even while program is not running. When, next time you start program, object will be there and it will have the same information as it had previously when program was running. Of course, you can get  same effect by writing information or to a file, but in spite of making everything an object it will be quite convenient to be able to declare an object persistent and have all details taken care of for you.