Dispatching refers to the process of triggering messages through CrossEngage. Our platform sends the request to your channel provider to send the campaign messages.
Sending is the campaign deployment handled by your channel provider (for example, Mailchimp, Mandrill, AppBoy, etc.). Once messages are delivered, your channel provider reports back with delivery statistics which is collected in Campaign Overview dashboard in CrossEngage.
The value for the metrics called "Sent" is namely the number of messages sent by your channel provider. In can be lower than the number of dispatched messages in case users are not reachable due to bounces or it takes more time to send the statistics from your channel provider to CrossEngage. For more reasons, please check Why is the "Sent" count lower than the segment size of my campaign?.