The Introduction is perhaps the most important chapter in your report.
Typically, the structure is:
Start broad, introducing the domain and why it is important
Narrow to the specific technology within the domain
Describe challenges
Briefly mention solutions that attempt to meet those challenges
Concisely say why those solutions are not sufficient
Note, the previous paragraphs set up your problem statement.
Then:
Describe the methods you used to address the problem (think verbs)
Give a high-level summary of the results - what you ended up with (think nouns)
Lastly:
Important: All of the above needs to be readable, have flow, taking the reader from the broad to the narrow, providing an understanding of why the domain and problem are important, and giving a good idea of what you did about the problem.
It is best to outline the Introduction before writing it in order to get the content and flow down. Do this at the paragraph level - think of topic sentences and supporting details.