Over time, I've developed rules for how I handle dimension travel. I use certain terms that, though seemingly self explanatory, may be more complex than they seem or might be somewhat... misnomer-ish...
To help with that, I have compiled a list of terms that I use to describe certain rules or phenomena my characters encounter while dimension traveling.

Dimension Doppelgangers: the person in a dimension that is a different version of you. Typically your dimension doppelgangers and you share a connection in body, mind, and sometimes fate. Has been described as a person's parallel, or mirror, in that dimension.

Doppelganger Trauma: The pain felt by all dimension doppelgangers that reside in the same dimension. When in the same dimension with any dimension doppelganger, whatever pain one of them feel the other feels. Under normal circumstances, any harm that comes onto one doppelganger, comes to the others.

Root Doppelganger: This is a term used only when more than one dimension doppelgangers are in the same dimension. This refers to the doppelganger that belongs to the dimension.  

Dimensional Lag: the lack of aging one experiences when in any dimension other than their home dimension.

Home Dimension: the dimension where you have and identity and the only dimension where you do not experience Dimensional Lag.

Dimension Disconnection: The act of isolating one's self from their home dimension and separating themselves from their identity. Without a home dimension one would experience permanent Dimensional Lag unless reconnected to a dimension of choice.

Dimension Wanderer: A term used to describe someone who is traveling through dimensions and has been disconnected from their home dimension.  

Dimensional Veil: The element of reality that separates/connects any dimension from any other dimension and the Dark Void. Is most often described as behaving like a fabric or membrane.

Dark Void: The lack of time and space that resides between dimensions. From some views it exists only from the perspective of dimensions as an empty shell made from other dimensions' veils.

Dimensional Tube: The means one uses to get from one dimension to the next through the Dark Void, usually entered through a portal, rift, or rip in the dimensional veil. It's made of a thin fusion of the two dimensions' veils.

Shades: Beings that usually reside in the Dark Void. They seep into the normal dimensions via  faulty dimensional tubes or rips in the veil that don't have another side. By its definition, Shades are not living creatures. They are barely visible in light but when in darker areas take a form that look more like a shade of color in the shape of a creature of some sort. They range from humanoid beings to demon like dogs. Some say they are reminiscence of the dead but it has been yet to be proven if they have consciousness at all.

Dimensi: A phenomena that happens with the multiple dimensions that an individual travels through. It is better known as the patterns between dimensions.

Dimension Collapse: When a veil between two or more dimensions breaks, disappears, cracks, or merges. The effect of such an event is the sudden appearance of areas, objects, and/or people from one of the two or more dimensions somewhere in another of the two or more dimensions. A dimension collapse has no known solution as of yet.

Connection To Reality/The Veil : Every concept has a signature in reality. Generally the concept of a non sentient object will have a different connection to reality than a sentient one. A being with sentience and a soul (in this world considered human) would have a line of dimension doppelgangers they're connected to. An animal doesn't have the same affect, though they are a living creature, they don't have the same connection to reality.

Shared Doppelganger: When a dimension houses more than one dimension doppelganger from the same line. Rare as it may be, and unbelievably hard to maintain, shared doppelgangers have a stronger connection to each other than normal dimension doppelgangers.

Dimensional Loop: A sequence of portals, each leading from one dimension to the next, eventually to come back around to the dimension it had been started at. The portals could be separated in any given dimension by time and/or space.

Dead World : A world which all of the remaining inhabitants would become dimensional wanderers if they left the dimension. Normally takes the form of a post apocalyptic environment and social structure. A dead world, by it's definition, can not support residents any longer, therefore a dimensional wanderer cannot connect themselves to a dead world. It is possible to revive a dead world, though it will never be the same.

Residents : The inhabitants of a given dimension, or the people connected to the dimension.

(Zuvorian) Artifact : An object that has been dimensionally modified by a Zuvorian but still remains an object. There are three types of artifacts; artifacts that have been modified to enhance its original purpose; artifacts that have been modified to be used for an alternate purpose than the object's original intent; and artifacts that have been modified in a way the requires a living being to be operated.
An artifact by definition can not have a soul or a piece of a soul embedded into it. It must remain an object. When a soul is embedded into an object, it is no longer the object but it is the vessel for the soul, a part of the person. The third kind of artifact it a loophole to this problem. Instead of the object itself having a soul, it uses the soul of the holder or the operator to act like it is a living thing.