FI (Financial Accounting)
CO(Controlling)
EC(Enterprise Controlling)
TR(Treasury)
IM (Investment Management)
HR (Human Resource)
SD (Sales and Distribution)
MM (Materials Management)
PM (Plant Maintenance)
PP (Production Planning)
QM - Quality Management
BW (Business Warehousing)
There are many industry specific solutions that SAP provides apart from the list of modules above which is ever growing.