Dissertations and theses offer new research by undergraduate and postgraduate students.They are a long, extended report and should include background research, methodology and experimental findings.
Not all dissertations are publicly available as some may include restricted content destined for commercial development.
By looking at existing dissertations you can see what's expected, including how to lay out and format your document. They are also a good source of reference lists on a topic and are a good indication of what has recently been researched in your chosen area.
University of Lincoln provides guidelines on what to include and how to format your assignments. Check Libguide assignments - Writing Development - Guides at University of Lincoln or talk to your supervisor if you need guidance.