Both editions of activeCollab - Small Biz and Corporate allow you to manage projects and collaborate with co-workers. The main difference between them is in the range of work that you can manage with each one, because of the difference in the number of features that each edition offers.
activeCollab Small Biz has basic project management and collaboration features (such as Checklists, Discussions, file sharing, etc.) that will enable you to organize your projects and to keep track of all recent events using activeCollab.
On the other hand, activeCollab Corporate offers more advanced project tools (such as Tickets, Pages, the Source Module, etc.), together with a few specialized Modules (like Invoicing, Time Tracking, Status messages) that will help you run your business more effectively.
You can see a table showing the full comparison of features supported by each edition on our Pricing page.