On Hold: Items "On Hold" commonly suggest that the communication is in process of being reviewed by your compliance officer. Once the communication has been approved by compliance you will receive an email stating that your newsletter has been approved by your compliance. Once approved the article is ready to be sent out to your contacts.
In Progress: "In progress" communications are still in the process of completion including drafts and uncompleted newsletters. Once all fields have been filled, the newsletter can be sent out to your contacts.