Versions are a version of your mailing. You can have just one version or you can make multiple versions of any mailing. Versions are useful if you want all or part of your mailing to be different for different customer groups. E.g. if we take the January edition of our Monthly Newsletter project, we need different versions of it for our bronze, silver and gold loyalty customers as the offers are different for each group. Or if you work internationally, you might need an English, French and Spanish version.