If you are unsure which type of abstract you should write, ask your instructor if the abstract is for a class or read other abstracts in your field or in the journal where you are submitting your article.
A double-blind study?
Introduction promises some results or useful information, but presents only suggestions, without revealing of all secrets. Remember, that there are word limits, which you should follow.
Your best bet in this case is to ask your instructor or refer to the instructions provided by the publisher. Never submit the abstract and research paper or any other type of work without proofreading and editing first.
For the purposes of writing an abstract, try grouping the main ideas of each section of the paper into a single sentence. The abstract SHOULD NOT contain: Lengthy background or contextual information, Redundant phrases, unnecessary adverbs and adjectives, and repetitive information; Acronyms or abbreviations, References to other literature [say something like, "current research shows that