When we run Firefox you will see how much memory it is using in task manager in processing tab. When you don't have work or Firefox and if you want to work on another program and also want to keep open Firefox then you have to Minimize Firefox. Now Minimized Firefox also use that much memory when it was open.
How Save Your Computer RAM Memory When Firefox Is Minimized?
This tip is very useful when you are working on a PC which do not have sufficient space to run more porgrame togather. This Mozilla Firefox tip helps you to save computer memory (RAM) when the internet browser is minimized. This allows windows to allocate more memory to other applications and games running on your system. This preference setting allows windows to swap out memory from a minimized Mozilla application.
Open Mozilla browser in windows OS
On the address bar type about:config
In the filter field type config.trim_on_minimize
There may be a default value False which prevent Windows from trimming the working set
Double click the key to toggle.