Masking SMS is a text message with the sender name in place of number and
the non-masking SMS is a text message without
the sender name in place of number, I mean receiver will see a 11-digit number,
not sender name.
The basic difference is to showing sender name or not.
Client base SMS service is client can send sms own marketing, notification etc.
Re-seller base sms service is re-seller can send own marketing purpose and can sale.