From "How to Write a Technical Paper: Structure and Style of the Epitome of your Research":

The introduction serves a twofold purpose. Firstly, it
gives the background on and motivation for your research,
establishing its importance. Secondly, it gives a summary and outline of your paper, telling readers what they
should expect to find in it.
When you write the background review, you should
consider including technological trends of the area, open
problems and recent promising developments. At this
point, you can introduce more specific terminology which
is not widely known. Provide good motivation for your
work, such as explaining its technological, research or economic importance. The motivation should not be elaborate; simply two or three good reasons are enough to
make your research important.
The summary should include a problem description,
which is slightly more detailed than in the abstract. The
summary should also include a description of your solution and some arguments on its impacts. In the description of your solution, include its key concepts and
categorize its approach.
Close your introduction with a description of your paper outline, what sections it contains and what the reader
will find in each. After completing the introduction, readers will decide if they want to continue.
Your paper should flow smoothly. Readers should never
feel as if they are missing information—a technical paper
is not a novel. A proper flow is to first set the context,
then present your proposal, then provide the verification,
and lastly wrap up with conclusions. Figure 1 gives the
main sections of a paper. Introduction, related work,
system model and problem description set the context,
followed by the presentation of your solution. Analysis,
simulation and experimentation make up the verification
part. Lastly, conclusions and future work make an evaluation of your solution according to the verification results.