ABAP

Dialog: Individual, interactive system access.

System: Background processing and communication within a system (such as RFC users for ALE, Workflow, TMS, and CUA).

Communication:Dialog-free communication for external RFC calls.

Service: Dialog user available to a larger, anonymous group of users.

Reference: General, non-person related users that allows the assignment of additional identical authorizations, such as for Internet users created with transaction SU01. No logon is possible.

SAP云平台

Business user vs technical user：

Kubernetes

也有User Account和Service account的概念。

用户帐户为用户提供账户标识，而服务账户为计算机进程和Kubernetes集群中运行的

Pod提供账户标识。两者的一个区别是作用范围：前者对应人的身份，与服务的namespace无关，因此用户账户是跨namespace的；而后者对应的是一个运行中程序的身份，因此与特定namespace相关。