In contrast, applications software (also called end-user programs) includes database programs, word processors, and spreadsheets. Figuratively speaking, applications software sits on top of systems software because it is unable to run without the operating system and system utilities.

Also see a diagram of n-tier application architecture in the quick reference section of Webopedia.

CRM Systems (CRM) - CRM2day.com
The #1 CRM portal for Customer Relationship Management and Marketing offering CRM news, events, CRM articles, white papers, analyst gurus, strategy views, CRM solutions and applications, CRM software and system reviews.

Webopedia's "Did You Know...?" Section
Use this Webopedia knowledge section for an in-depth overview of specific technologies and occurrences in the areas of Computer Science, The Internet, and Computer Hardware and Software.

Webopedia's Quick Reference Section
Use this Webopedia reference section for information on common Internet and computer facts and occurrences.