In Mac OS, the System Preferences controls how your Mac runs and behaives, some settings change users specific settings such as Desktop and Finder, while other affect the entire system. If a padlock icon appears in the bottom left of a preference window, then you will need Administrator rights to change those settings.
For example, if you wanted to change Desktop and Screen Saver you get the following
window with a list of possible settings.
Users & Groups - Create, modify and delete user accounts, groups, login options, Directory Services.
Accessibility - Manage ease of use tools and settings including Display, Zoom, Magnifier, On-Screen keyboard, Narrator, High Contrast.
Screen Time - Monitor how much time spent with apps and set restrictions. See HT208982.
Extensions - Manage apple and third party externsions and any widgets to show in Today view.
Security & Privacy - Set Password, app store security. Configure network protection against unauthorised access to your system. File Vault for file system encryption.
