Access levels sets what pages you are allowing this user to view and edit.  If you can view the page you can edit the page.  Suggestion:  Create a test user other than the administrator.  Use the test user log in and set the different access levels.  This will allow you to become familiar with what users see when logged into your company. 

Remember Access Level determines what pages are viewed and edited.  The Access Filter determines what tickets based on First and Last Name this user can see.