What is the meaning of the system user term in Plesk?

Question

What is the meaning of a "system user"or "sysuser" in Plesk? What can such a user do?

Answer

With the creation of each Subscription, Plesk creates a System user, which is a user created for use within the Plesk system, however Plesk GUI access is not possible for it by design.

The system user access credentials can be used for connecting to the server through FTP and SSH access (if enabled for the Subscription.

In addition, all operations with files and directories in Plesk are performed on behalf of the system user of the Subscription. For example, when a customer adds a new file in File Manager, the system user of the Subscription becomes the owner of the file.

For additional details, visit Plesk Administrator Guide and Getting Started Guide

Since system users do not have access to Plesk GUI by design, if you want to allow someone access to the Plesk interface, you have to create a new Additional User

Alternatively, you can or create a separate Customer and change the Subscription owner to become that new Customer, because Customer accounts in Plesk do have access to the Plesk GUI.

Additional information

Customer Account Administration | Plesk Obsidian documentation

Managing Additional User Accounts | Plesk Obsidian documentation