System - among many other things - refers to the collective of alters within one body inhabited by multiple people.

The context is almost always the highly stigmatized mental disorders D.I.D. (Dissociative Identity Disorder) or O.S.D.D. (Otherwise Specified Dissociative Disorder) which both share the defining symptom of multiple alternate states of conciousnesses, colloquially referred to as alters or "multiple personalities". These alters often have different memories, abilities, etc. and can be just as different and well-defined as any other people in the world.

System refers to the collective of alters within one body.

A buzz word being used to refer to creators and influencers forming or encouraging unhealthy relationships with their fans. Usually used in the context of young audiences feeling they have a relationship with the influencer due to the huge amount of the influencer’s content they consume. The influencer in question, however, is unaware of the fan’s existence other than the general knowledge of having fans. Common examples include Dream and his stans. These relationships are exacerbated by the influencers confirming they have more than a creator-to-viewer relationship.

The word is circulating due to various YouTube essays about the phenomenon using the word, and therefore people who enjoy complaining about influencers repeating what they heard in the video in any comments section they can find.

High powered, premium stereo system in a car, truck or van, capable of large amounts of bass and treble.

a set of things working together as parts of a mechanism or an interconnecting network; a complex whole.
"the state railway system"
synonyms: structure, organization, order, arrangement, complex, apparatus, network

Can mean a lot of things. Notably:

Computer system: A somewhat more technical term for describing a rig, usually including a processor, hard disk, monitor, RAM, cards, etc.

A weather system: An area that has an airmass of notably high or low air pressure; can be affected by thermodynamic interactions with the atmosphere, bodies of water, etc.

System: In general, anything that unifies more than one thing or organizes them. Eg: healthcare system, etc.

System (of a Down): System is often used as an abbreviation for the name of this kick-ass band because you want to save time for discussing how awesome they are.

you are system if you are raw at basketball. and a replacement for swag.