Plasma activities are a way of separating different workflows or types of operations with the computer depending on various factors (is it reading or writing? surfing the internet or watching videos? studying or playing? history or language? Latin or German? etc etc).
Each activity can have its own desktop widgets, wallpaper etc.
It would be interesting to be able to separate between applications, windows and files by opening them by default in different activities, instead of the present behavior where each is opened only in the current activity.
For example, at the present I have 4 different activities, depending on my present interests. I want some applications to be available in all activities (Firefox, Dolphin), some in just one activity (the terminal), and I would also like that some files are opened in a different activity, even if opened with the same application.
I am posting this in order to provide an answer, but I will edit the answer over time, because there are different degrees of complexity that I haven't yet completely mastered.


