We return with another trick, this being one of those that few people know but that may be useful for some tasks, although I honestly have been able to get little performance.
If you want to move a window that is in the background, what you should do is press and hold the CMD key and then move it, which will cause the window in the foreground to remain active.
As I have already said, this is not a very common behavior, but perhaps you find it useful.
Source | OS X Daily