Call barring lets you stop certain calls (international calls, for example) being made to or from your mobile phone. So it can help you limit your own spending or prevent someone misusing your phone.
Call divert lets you direct incoming calls to another number - ideal if you want a friend or colleague to handle your calls without actually giving them your mobile.
With call holding and call waiting, you can juggle more than one phone call. If you're already mid-conversation, Call holding allows you to put one caller on hold while you make or receive another call.
Call waiting uses a soft dual-tone bleep to let you know when another caller is trying to contact you.
