How do I lock my mac easily
I am really frustrated. Most of the time I do not want my iMac at home to require a password. But sometimes I have visitors or workmen and I do want the screen locked. I used to have this little "padlock" icon in the menu bar that I could click and choose "lock screen". Then you needed the logon password to access. That disappeared and I don't know how to get it back. I am using HighSierra.
iMac, macOS Sierra (10.12.5)