A Distribution is a way of sharing data, but is different to a 'Send' in the following ways;
Data will not expire. With a normal data send, the data will expire and be deleted from the server up to 30 days from the date it was sent.
The recipients can change over time. A normal data send is sent to one or more recipients and those recipients can download the data. Although a normal send can be forwarded, that can only occur up until data expires. Recipients can only be removed by revoking their access. So if you want to send the same data to another recipient after data has expired, you would have to initiate a fresh transaction. Using a Distribution you can add and remove recipients flexibly meaning you can control who has access to download the data that has been uploaded.
Version control is available (if required). This means that when a new version is created, access to the old version is locked and email notification goes out to all users.
Certain MX users are permitted to control the Distribution content and audience (Supervisors) and everyone else is a recipient of the data. When a new version is created, access to the old version is locked and email notification goes out to all users.
You would need to speak to an Administrator for your account, to see if they have Distributions as part of their package and to create the initial Distribution for you to work with.
Go to your Account information page to view all Administrators for the current MX customer.