How would you design a user interface for container tabs that non-technical users can understand? Something like container windows, isolating different browser

How would you design a user interface for container tabs that non-technical users can understand? Something like container windows, isolating different browser windows instead of tabs, might be a clear way to visibly show the separation to the user. In one window, they can log into their work Gmail. In another window they can log into their personal Gmail without any Google cookie confusion.