A more thorough explanation:

Inadmissible evidence is evidence that cannot be presented to a judge or jury to prove a party's claim. The Federal Rules of Evidence determine whether evidence is admissible or not. Evidence may be inadmissible if it is irrelevant, violates privilege or public policy, is unlawfully obtained, or if the probative value is outweighed by the danger of unfair prejudice, confusion, or waste of time.

• Relevant evidence is admissible, but irrelevant evidence is inadmissible. For example, in a case about a car accident, evidence about the weather conditions at the time of the accident is relevant, but evidence about the driver's favorite color is irrelevant.
• Evidence protected by privilege, such as attorney-client privilege, cannot be admitted if the holder of the privilege refuses to disclose information. For example, a lawyer cannot be forced to testify about a conversation with their client.
• Hearsay evidence, which is an out-of-court statement made to prove the truth of the matter asserted, is generally inadmissible unless it falls within an exception or exclusion set out in the Federal Rules or a federal statute. For example, a witness cannot testify about what someone else told them about the case.
• Character evidence is usually inadmissible, but there are exceptions. For example, evidence of a person's prior criminal convictions may be admissible to impeach their credibility as a witness.

These examples illustrate how evidence can be inadmissible for various reasons, such as being irrelevant, violating privilege, or being hearsay. It is important to understand the rules of evidence to ensure that only admissible evidence is presented in court.