Elasticsearch fscrawler laravel

Hello elastic community
I have a problem
I developed a laravel project that I integrated elasticsearch and fscrawler for searching indexed files then I deployed the project on an ubuntu server system with an nginx server
My problem is that my server has 24GB RAM and when I check I see that the RAM is already saturated even though the project is in the test phase which means that there is no maximum number of users
I would like to have your advice why my RAM is already saturated even though there are not enough users no files to process
And I did the same process on another server with a 6GB RAM which is not saturated even when using
I ask for your advice what could be the cause for the server RAM (ubuntu server virtual machine) to be already saturated even without using

What exactly is running on the server?

Note that it's better to have only Elasticsearch running on the machine. It will use all available memory for caching files for example, so it will serve your users faster.