I'm reading a manual here about the "create global object" permission,
But what exactly is a global object, it appears to be part of a session, but still too abstract to me.
A Global object is a object created such that it can be used by many processes or threads, even those not started within the users session.
Its a systems engineering concept, but whats important to you in terms of security is that a global object could be used by or alter the function of processes in another users session (even the system or service sessions). by doing so, it allows the user to affect stuff beyond their individual session, and as a result, it may be desirable to lock that functionality down. as a general rule, locking a user down to their own session is considered desirable on many multi-user systems, so no one can inadvertently take the system down, install malware into system-space, etc.