Why is client-side validation a security risk as opposed to server-side validation?

Question

I don\'t quite understand why client side validation is a potential security risk or more of a security risk than server side validation? Can someone give me some scenarios

Answer 1

If you do validation only in client-side, someone may disable javascript (or change the js code, with firebug, for example). So, all validations made in js would be useless and user can insert invalid data in your system.