How does the Task Manager's RAM usage works?

[Spectralware]

Hey guys! I am having a really tough time figuring wth is wrong with the task manager in Windows 10.

First off, i just wanted to say i don't know much about RAM, but i can't understand how, say i have 8GB RAM, the task manager says it's using 40% (which is around 3.2Gb) but if i count the usage of every process, it doesn't even reach 20%. Why is it telling me it is using something.... When it isn't? Is it because the OS itself uses some RAM and the task manager won't display it? I am confused.

 

[k1114]

On the performance tab you should see a link to open resource monitor. This will give a more detailed breakdown. You will see different columns: commit, working set, etc. If you put your mouse over it, it will have a popup that explains it. You will notice the private amount is the same as task manager and that it's not the actual ram usage amount.