Hi,
According to the following site, it seems the differences between the two plans are:
1. Active Directory integration:
Manage user credentials and permissions. Single sign-on and synchronization with Active Directory.
2. Intranet site for your teams:
SharePoint sites provide workspaces with customizable security settings for individual teams within the organization.
3. Site mailboxes:
Store and share email and documents in project-specific folders, allowing for easier team collaboration.
http://office.microsoft.com/en-us/business/compare-office-for-business-plans-FX102918419.aspx
Both plans have Free trial version. Before you purchase the products, you can give it a try.
Best regards,
Rex Zhang
TechNet Community Support
