Window Manager is a software that takes care of your Windows / GUI Frames used by your applications, only if you use Linux as your operating system, there are so many you are spoiled for choices. Here I will list some of my favorites including pseudo ones for Mac and Windows.
PaperWM this has the best Window management execution, though this is shell extension on top of GNOME desktop, it works well and mostly well kept updated. The idea is like Fedwiki approach, any window or application you launch will launched next to current application like a Lineup, frames will be launched full height, you have keys to control the width of the frame, there is option to split window horizontally, duplicate windows, and many more functionality. site 
PaperWM was inspired by 10gui
Notion, find description here Killed not by Google
PaperWM.spoon site brings PaperWM concepts to Mac using a software Hammerspoon site . It works well most of the time but also messes up.
Powertoys for Windows has some Window Manager functionality much like Notion, you can create frames and add GUI windows into it, it is less fluid, but works well.