Change sets versus packages for unrelated orgs
Key Takeaway
Change sets travel only between orgs affiliated with the same production org, such as a production org and its sandboxes. An org that isn't affiliated with your production org has no deployment connection to your orgs, so a change set can't reach it.
A change set moves customizations from one Salesforce org to another. For example, you can build and test a new object in a sandbox and then move it to your production org in a change set. Whether a change set can reach a target org depends on how that org relates to your production org.
What a change set carries
A change set carries only changes that you can make through the Setup menu. It holds information about the org, not data, so you can't use a change set to upload a list of contact records.