The major modules in SAP CRM are marketing, sales, service and analytics. On the user interface you have IC WebClient, Web Channel and Mobile, both internal and external to the company. There are also sub-modules when you combine the major modules with user interfaces
SAP now are moving away from describing their system as a set of modules, and now are using the term 'solutions', which is much better. If you visit SAP's website you will find that they have structured their Solutions tab as follows:

*Financials
*Human Resources
*Customer Relationship Management
*Supplier Relationship Management
*Product Lifecycle Management
*Supply Chain Management
*Business Intelligence ...more