Virtual numbers for SMS are numbers that you can use to receive incoming SMS and send outgoing SMS.
You can send outgoing SMS only if you have a number with SMS feature. You can send them from your account at Freezvon in "Virtual Phone numbers --> Send SMS", to any international destination except for the ones that are disallowed by local operators.
To check whether your number accepts international incoming SMS, see the article: "Who can send SMS to a virtual phone number".