What is the difference between an abstract and an introduction for a scientific research poster/report?

[tLadyStormyt]

I have my abstract written following the guidelines I was given by my professor. Now, I need to write the introduction, but I don't know what all is supposed to be in it? My biggest concern is whether or not I should repeat some of the things I discussed briefly in the abstract and be more in depth about them when writing the introduction.

[tNICKJALLTHEWAYt]

Abstract is the portion where u describe ur work very briefly,like what u did in the experiments and what u have concluded with the paper. Introduction means it is the introduction of the work,like why u have selected that topic. for example if u are studying about antimicrobial drugs,then in the abstract,u will write what is the drug used for your study and how it is active against certain microbes.but in introduction u have to mention, what are antimicrobial drugs and previous people conclusion about the drugs,existence of certain diseases which that drug can cure.....