I am primarily using Firefox as my web browser. I have noticed that after some tabs having been opened and closed the memory usage of Firefox becomes larger and larger.
This fact often leads me to crash it (deliberately using the task manager) and to open it again selecting only some of the tabs I need. There are cases where I open all my previously open tabs. The funny thing is that even in this case, the memory usage is by far less than what it was before shutting Firefox down.
So my question is why is this happening? Why does the closing of the tabs not help (at least not that much)? Is there a way to reduce the memory usage without shutting Firefox down?