Cache Management Ubuntu 18.04 LTS

I have a Laravel 5.6 (including NodeJS) application hosted on AWS cloud (Ubuntu 18 LTS) with available RAM of upto 4GB.

But I am observing the available amount of RAM decreasing due to some unknown reasons to me.

I saw the output of free -m command via terminal and the results show more than 1GB of cached data.

Could you guys illuminate me more into that as to why cache is increasing.

Can I browse to that folder if cache is being stored temporarily.

Thank You in anticipation.

via Chebli Mohamed