The term Business Software includes software applications that provide fundamental functions for a company's business processes. These typically include ERP, PPC and Financial Accountancy, but increasingly also DMS and ECM systems. Apart from these - for many companies generally important - systems, special branch applications, such as CAD systems, count towards business software.
Text processing, spread sheet and e-mail / fax solutions on the other hand fall into the category office-based application. These are usually also used within a company, but are normally not involved in key processes and are not essential.