outline what each Severity Level means.

Low:  General question or problem/issue.
medium:  General question or issue that you feel could impact your work.
High:  Time sensitive question/problem. Slightly impacting your work currently. 
Urgent:  Website or work is impacted to point you feel the overall effectiveness of site could be compromised.
Emergency: Site is having major issues but not competely down.  Work around possible.
Critical:  Entire website is down.  Email is down. No work around.