Report Templates: Django templates used to built your report documents.
Report Documents: Instances of the rendered templates providing downloadable documents like PDF, CSV or Excel files.
Vulnerability: Security related weakness found during a project (e.g. SQL-Injection)
Finding: Instance of a vulnerability (e.g. SQL-Injection in the username field)
Vulnerability Templates: a predefined set of vulnerabilities that are used across projects. Useful to prevent copy&paste the same descriptions and recommendations all over again.
Advisories: Findings in third party software that you may want to report to their vendors.
Company: Usually, your customer that ordered the assessment.