The system is a divine power you higher dimension beings wish for. As you know with a system you can be a god. The goal of a system is to ensure that you stand atop everything, some systems may have shops, inventories, status, skills, jobs, quests, and anything you can imagine.
So now that you have a somewhat basic understanding of a system let me explain it to you through science. If technology evolves to a stage that we don't need physical phones and computers and our bodies have phones and computers a system could very well be real. Imagine that you have a system status it can be projected as a hologram in your mind thanks to the computer in your head or body. The status can be based on your body, you have a computer in your body that is able to scan your body so displaying your status is easy. The shop or system store can work like AMAZON. The items you buy can be delivered to you via teleportation. Teleportation, Science evolves to a level that even Daoists would fear. Through the manipulation of space, teleportation can be reality. Inventory is easy because it can also be teleportation but it teleports your items to your personal space that you own.
Alas, my time is up if you want me to explain anything through Daoism, leave it in the dimensional rift, called the comments.
If you want me to explain anything else leave it also in the dimensional rift.