Online Technical Writing: Abstracts
http://www.io.com/~hcexres/tcm1603/acchtml/abstrax.html

Illuminati Online

Abstract:

An abstract is a summary of a body of information. Sometimes, abstracts are in fact called summaries--sometimes, executive summaries or executive abstracts. There are different kinds of abstracts—your technical report uses two types: the descriptive abstract and the informative abstract.