If you are using a Desktop Enviromnet and or login manager, (GNOME,KDE,XFCE,LXDE) almost all of them have a lock screen function where you have to type in your password to get back to your programs.

However since that is really simple i sense your problem is more complex / different.

If you are using a Desktop Environment or login manager, (GNOME,KDE,XFCE,LXDE) almost all of them have a lock screen function where you have to type in your password to get back to your programs.

However since that is really simple I sense your problem is more complex / different.