§ 2401 Definition of "relevant evidence".

Relevant evidence is any evidence that helps prove or disprove something that actually matters in the case. If a piece of evidence makes an important fact more likely to be true, or less likely to be true, then it counts as relevant.

The evidence does not have to prove the fact all by itself. It just needs to move the needle a little bit, either making something seem more likely or less likely than it would without that evidence. Even a small connection can be enough to make evidence relevant under this rule.

This matters in a case because only relevant evidence is allowed to be considered in court in most situations. If evidence has nothing to do with the facts that matter to the case, it usually will not be let in. This rule sets the basic test judges use to decide whether evidence has enough connection to the case to be worth considering.