There are three Origins that all characters can select. Below is an explanation of each and examples of where each may come from and how they fit into the Outlands.

Prime / Primer

Primers are those born in the Prime Material Plane. Most primers are mortal and are usually born on planets or other similar celestial bodies. The Prime Material Plane is also known as the 'Mortal Plane' or 'Mortal World' by some cosmologists.

Worlds of the Prime Material Plane

Worlds of the Prime Material Plane were believed to be encased by powerful crystal structures which were surrounded by an infinite expanse of universal fluid known as phlogiston. The individual worlds of the Prime Material Plane were not located near one another, but some were aware of one another to a degree and wizards or other similar beings could move between worlds by magical means.

Aebrynis (Birthright / Spelljammer)
Athas (Dark Sun)
Avaras (Planescape)
Eberron (Eberron)
Io's Blood Isles (Council of Wyrms)
Krynn (Dragonlance)
Mystara (DnD 1E / Blackmoor)
Oerth (Greyhawk)
Ortho (Planescape / Harmonium)
Toril (Forgotten Realms)
Wildspace (Space between worlds / overlap between Material and Astral Plane)

Planar

Planars are those born anywhere outside of the Prime Material Plane. Some planars were immortal, though many were also mortals born in the various planes. Elves and goblins born in the Feywilds, and Gith born in the Astral Planes were examples of this. The rules of existence were different for those created in the planes, meaning that planars could be bound, summoned, or utilized in various ways with magic that Primes were not necessarily as easily bound to.

Feywilds

Also known as the Plane of Faeries was an echo of the Prime Material Plane suffused with potent magic and unrestrained emotional energy. It was the place in which Fey, Elves, and Eldarin originated and from. The Feywild consists of the hopes, dreams, emotions, desires, and vices of the Prime, all in an unrestrained and breathtakingly beautiful environment. Various sections of the Feywild echoed the various worlds of the Prime Material Plane.

Elves, Dryads, Goblins, and Hags are examples of creatures that may hail from the Feywilds.

Astrazalian (City of Starlight)
Brokenstone Vale
Evermeet (Former Faerunian city now in the Feywilds)
Feydark (Fey reflection of the Underdark)
Iliyanbruen
Mithrendain (The Autumn City)
Nachtur
Realm of Malabog
Seelie Court (Also exists in Arborea)
Unseelie Court (Also exists in Pandemonium)

Shadowfell

Similar to the Feywilds, the Shadowfell was a dark and twisted reflection of the Prime Material Plane. Also known as the Plane of Shadow, it was a bleak and desolate place full of decay and death. Souls departing for the Fugue Plane often found themselves in the Shadowfell along the way. It was a dimmension lacking color, light, sun, moon, and stars in most places. Light sources only lilluminated half the distance it normally would, flames produced less heat, and dread and lethargy gripped those visitors to the plane.

Chaulssin
Chaul'mur'ssin
Evernight
Gloomwrought
Mausoleum of Pain (Domain of Null - connected to Mausoleum of Pain in the Outlands)
Mulsantir
Shadow Keep (Domain of Mask)
Shadow Swamp
Sphur Upra
Towers of Night (Domain of Shar)
Thultanthar (City of Shade)
Ravenloft (Curse of Strahd)

Astral Plane

Serves as a conduit to the Outer Planes, and surrounds the Material Plane but does not overlap it. Time flowed the same in the Astral Plane as it did in the Material Plane, and it could be entered at almost in point in the Material Plane with the aid of magic or certain technology. It is a barren and desolate place of absolute nothingness and void, with occasional chunks of matter.

Wildspace
Astral Sea
Deep Wilds

Ethereal Plane

Exists between the Prime Material Plane and the Inner Planes, and also overlaps each.

Border Ethereal
Deep Ethereal

Inner Planes

A subset of the known planes of existence consisting of the fundamental building blocks of matter, and energy for the entire multiverse. The inner Planes consisted of the various Elemental and Energy planes. At the borders of each plane of existence were para-elemental and quasi-elemental planes that combined the neighboring regions' properties together.

Elemental Planes

Plane of Air
Plane of Earth
Plane of Fire
Plane of Water

Para-Elemental Planes

Fountains of Creation (Plane of Magma / Fire and Earth)
Swamp of Oblivion (Plane of Ooze / Water and Earth)
Frostfell (Plane of Ice / Water and Air)
Great Conflagration (Plane of Smoke / Fire and Air)

Quasi-Elemental Planes

Plane of Radiance (Fire and Positive)
Plane of Minerals (Earth and Positive)
Plane of Lightning (Air and Positive)
Plane of Steam (Water and Positive)
Plane of Salt (Water and Negative)
Plane of Dust (Earth and Negative)
Plane of Ash (Fire and Negative)
Plane of Vacuum (Air and Negative)

Energy Planes

Positive Energy Plane
Negative Energy Plane

Outer Planes

The Outer Planes consisted of various planes of existence which were based off of the multiversial axioms of morality and ethics. Each individual plane represented a fusion of law, chaos, goodness, evil, and/or neutrality.

The Abyss (Chaotic Evil)
Acheron (Lawful Evil / Lawful Neutral)
Arborea/Olympus (Chaotic Good)
Arcadia (Lawful Good / Lawful Neutral)
Beastlands (Neutral Good / Chaotic Good)
Bytopia (Split - Lawful Good / Neutral Good)
Concordant Oppostion (The Outlands) (True Neutral)
Elysium (Neutral Good)
Gehenna (Lawful Evil / Neutral Evil)
Hades (Neutral Evil)
Limbo (Chaotic Neutral)
Nine Hells (Lawful Evil)
Mechanus (Lawful Neutral)
Pandemonium (Chaotic Neutral / Chaotic Evil)
Seven Heavens (Mount Celestia) (Lawful Good)
Tartarus/Carceri (Neutral Evil / Chaotic Evil)
Ysgard (Chaotic Good / Chaotic Neutral)

Blotter

Blotters are individuals that have no history. They simply came into being one day. Perhaps they have simply forgotten their history, or maybe there are other forces at work?