From e-Learning Documentation
Site Info is the tool that allows for the control of many aspects of the course. This tool cannot be removed from the Toolbar because if its importance to the course. In this tool, you can select which tools to use in the course, which tools to display to students, create and manage groups, add participants and bring in content from other courses in which you are an Instructor.
You will see here the content that is on your Home Page. Beneath that content you will see a list of all course participants, including the Role and Status. Beneath the list of Participants is a brief description of each of the Roles. A much more complete and accurate description of roles can be found at Participants - Overview of all Roles
While Site Info is valuable to instructors, there is little of value to students. Many instructors choose to hide the tool from the students. See "Page Order" for instructions on hiding tools.
Edit Site Information
This option allows you to edit information that is displayed to the students on your Home Page. This is identical to clicking on Options on the Home Page and making your edits there. But within "Edit Site Information" you can also edit certain information such as a contact information. If all contact information is provided elsewhere in the course, students get no added benefit from seeing the Site Info tool.