The purpose of this chapter is to make clearer the meaning behind the concepts of "standard application package" and "enterprise system". There is today a confusion in our IS field about the connection between the two concepts and how they have appeared historically? The main idea is to contrast them against each other and in this sense to study which opportunities organizations and companies can achieve with these two different IT environments. This transparency will give business and IT people a better understanding for managing investments in information systems more professionally. The research approach is characterized as "consumable research" (Robey, and Markus, Information Resources Management Journal, 11(1): 7-15, 1998) based on theoretical knowledge integrated with business practice from the IS field. Our background is through working with practical methods for customer involvement (purchasing, implementation, maintenance) as well as performing vendor studies of the software application industry.