Fast user switching enables more than one user login session at a time, but comes at the cost that memory and CPU resources are still required for other login sessions.
users
Is logging out and back in again a good way to deal with problems? Although it can be, it might not do what you think it does any more.
The first version of its predecessor, NetInfo, also handled DNS lookups. When they failed, users found they were locked out of everything else. This has improved!
Accessing information about you as a user and a great deal more, using the Advanced Options dialog for user accounts, and Directory Utility.
If anyone recommends that you change the Advanced Options for a user, please read this first. It could save you a lot of pain and grief.
Many problems result from settings within your user account, or in your Home folder. Creating a new user helps you work out where the problem lies, and can work around the problem itself.
Why does almost every Mac user use their system in an admin role? Shouldn’t macOS encourage us to be ‘normal’ users?
When should you create a new user, and how should you delete them?
The Eclectic Light Company 