Office 365 service comparison
Over the years I've blogged about how to compare the features in Office 365 across services. By coincidence I came across a brilliant page on TechNet, where you can filter and compare the features of Office 365 plans, Office 365 services, and on-premises products.
Visit the Office 365 Service Descriptions in the TechNet library for detailed descriptions of the services and features that are available with Office 365. The feature tables in the Office 365 Service Descriptions also include footnotes that provide additional information about specific plans.
You may also want to view the full-size workbook.