The Team edition is meant for the Contracts team to be able to manage contracts for their own organization and with some limited ability to provide access to external users. Typically these teams are anywhere from a single contract manager (with other reviewers and power users) to a group of 5-10 contract managers (with up to 50 reviewers and power users).
The Business edition is for mid-size organizations that want to implement contract management processes and extend them to Sales, Procurement and other areas of the business with self service capabilities, contract request capabilities, extensive support of business process activities, obligation and milestones for all business users and self-initiated business review, technical review and other processes managed within the system.
The Enterprise edition is for mid-size to large organizations that includes all of the features and functionality of the business edition but extends it with contracts business intelligence, extensive support for compliance and business analytics. There is also support for clause management.