Client side validation, say for example used to validate any logical or prefixed format of data, like ZIP code or name which contains numbers.
Server side validation - when you want to validate data from server persists data, like against database. e.g whether user id/passwords matches, this validation is done against the registered values from server.
Sorry, I didn't know that, thanks Carol & Eric for letting me know the various possibilities of JS usage and execution, its not only for browsers (though Netscape people invented it for browsers )
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com