Any fact from which, either by itself or in connection with other fact

Any fact from which, either by itself or in connection with other facts, the existence, non-existence, nature or extent of any right, liability, or disability, asserted or denied in any suit or proceeding, necessarily follows is known as :

Relevant fact.
Irrelevant fact.
Fact in issue.
Fact in law.
This question was previously asked in
UPSC CISF-AC-EXE – 2022
The definition provided in the question precisely matches the definition of a “Fact in issue” as per the Indian Evidence Act, 1872.
Section 3 of the Indian Evidence Act, 1872 defines several terms. The expression “facts in issue” is defined as follows: “The expression ‘facts in issue’ means and includes any fact from which, either by itself or in connection with other facts, the existence, non-existence, nature or extent of any right, liability, or disability, asserted or denied in any suit or proceeding, necessarily follows.”
“Relevant fact” is defined as one fact being connected with another in any of the ways referred to in the Act’s provisions on relevancy. Facts in issue are the principal facts that a party must prove to establish their claim or defence, forming the points of contention in the suit or proceeding. Relevant facts are those that tend to prove or disprove the facts in issue.