When you use the computer, probably running many software, each of them needs ram memory. RAM is very important , because the faster the frequency of the RAM the faster the software runs. In this tutorial we will move Firefox to your hard drive when you minimize it. When we do that, firefox will take up much less ram memory.
Open a new tab and type in about:config in the address bar. After this will appear warning message, click I´ll be careful, I promise !. In about:config settings right click anywhere and select New-> Boolean, as shown below
In New Boolean Value type config.trim_on_minimize and set it to true.
Restart Firefox and these settings will take effect.