What is the committed RAM?

I noticed in the system tray that something is guaranteed in the main memory:

I wonder if the part of the memory is that you can't use a system lock because of a system lock, if that should be the case, is there a way to bypass this lock so you can use the full RAM?

I don't know how much RAM is built in to make this a laptop.

I'm sorry about my grammar and spelling mistakes.

You have 4GB of RAM and apparently a free slot.

The system manages and guarantees what is completely normal.

Look mMn. Everything looks fine.