Since Moodle pages require Guest Access, every resource or activity on the Moodle page will be visible to everyone (enrolled students, parents, administrators, etc.).
For various reasons, resources might need to be restricted unless the student meets the stated criteria.
The following tutorials are commonly used restrictions.
Restrict Access to a certain GROUP
for Differentiated Resources
For courses that serve more than one audience, differentiated resources can be restricted so that the intended audience only sees their resource. Rather than add every group/period that this applies to each time, a Grouping simplifies this process.
for Modified Content
For students whose IEP or accommodation requires modified content, such as Reduced Answers and/or Simplified Wording, a group can be created to restrict access to the modified content so that its' hidden from the general education students. This essentially lets you have two versions of the same assessment or resource, but each version is only visible to the applicable students.
for Copyrighted Material
For resources that are copyrighted and should not be made available to all web-users since Moodle is open for guest access, resources can be restricted so that only enrolled users can view/access them. Examples or resources to restrict might include Textbook PDF (which does not require sign in for access) and self-purchased lessons such as those from Teachers Pay Teachers.