Difference between Unknown and Terra Incognita

UNKNOWN vs TERRA INCOGNITA: NOUN

A variable whose values are solutions of an equation
An unknown and unexplored region
Anyone who does not belong in the environment in which they are found
A person of no identity; a nonentity
That which is unknown.
Something that is not known.
A person who is not well known, as to the general public.
An unknown person, especially an Unknown Soldier.
A quantity of unknown numerical value.
A variable (usually x, y or z) whose value is to be found.
One who or that which is unknown.
Any fact or place about which nothing is known (as in the phrase "into the unknown").

Not known; not become an object of knowledge; not recognized, discovered, or found out.
Unknown in this sense is often used in the predicate, followed by to: as, a man unknown to fame; a fact unknown to the public. In this use it is also often used absolntely: as, unknown to me (elliptically for it being unknown to me), he made a new contract.
Not ascertained, with relation to extent, degree, quantity, or the like; hence, incalculable; inexpressible; immense.
Not to be made known, expressed, or communicated.
Not having had sexual commerce.

Unsung, Unbeknownst, Unsuspected, Nameless, Unnamed, Unfamiliar, Uncharted, Anonymous, Unexplored, Unmapped, Obscure, Undiscovered, Unknowable, Unidentified, Unknown quantity

Untraveled, Palaeolithic, Tabula rasa, Liminal, Unmapped, Untrodden, Unchartered, Unfamiliar, Landmass, Realm, Prehistory, Unexplored, Uncharted, Unknown region, Unknown

Unsung, Unbeknownst, Unsuspected, Nameless, Unnamed, Unfamiliar, Uncharted, Anonymous, Unexplored, Unmapped, Obscure, Undiscovered, Unknowable, Unidentified, Unknown quantity

Illimitable, Untraveled, Palaeolithic, Tabula rasa, Liminal, Unmapped, Untrodden, Unchartered, Unfamiliar, Landmass, Realm, Prehistory, Unexplored, Uncharted, Unknown

In the previous example we found an unknown side but we can also use the Law of Sines to find an unknown angle.
Unknown If yes go to page two of application if yes or unknown staff needs to attach routing slip.
Administrative Issues Unknown Scoring Time required: unknown Clinical Utility The general information obtainable on the procedure suggests that the concept and practices have merit.
Tomb of the Unknown Warrior was born, other countries began to honor their unknown dead with symbolic tombs of their own.
Chemical preservatives should never be added to unknown or untreated liquid wastes and to samples of unknown matrix or source.
The treatment of unknown types has not changed: the unknown types are treated as binary.
Take an unknown solid from your assistants and please DO NOT forget to write your unknown number in your lab reports.
Pinho is out of commission due to an unknown injury, and it is unknown how long he will be debilitated.
The proportions of men with unknown numbers of sexual partners or unknown HIV status were underrepresented in both samples.
Currently Unknown IDEM Currently unknown due to the need for future dredge funding.

The meaning of terra incognita depends no less on the kind of knowledge that we are considering.
Formally, though, the serials produced on cable in the past decade are leading the form to an exciting terra incognita.
As the global energy economy transitions toward a more statist and mercantilist system, policymakers are likely to find themselves operating in terra incognita.
You do not have to discover all Terra Incognita yourself, as TI can be automatically uncovered via spread of discovery.
Reading the Kenyan Swahili Prose Works: A Terra Incognita in Swahili Literature.
Greek concept of terra incognita as an extension of the African continent.
Much of the early West in those early days was terra incognita.
Developer Terra Incognita creating new resort in north of country.
Pro Johanne Caboto et filiis suis super terra incognita investiganda.
My good friend Richard Fisher refers to terra incognita.