Production is the server that people see when they view the public website. Once you are comfortable with the web editing process, you'll make most of your changes here so they are visible on the website.
Development is is a test server at http://www.webdev.earlham.edu. It is the server that we as web editors and trainers can use as a testing ground for "what if" questions without worry of impacting the production website. For safety, there is no connection between the two systems. This means that any changes you develop on the test server and would like to see on the production server must be made there as well.