Glossary
Testimony
A statement made under oath by a witness: at a deposition, hearing, or trial. Testimony is one of the most common forms of evidence, but it's also the most prone to memory error and bias.
Witness testimony comes in two main forms: direct examination (the side who called the witness asks open-ended questions) and cross-examination (the other side gets to ask leading questions designed to challenge the witness's story).
Testimony has to be based on personal knowledge: what the witness actually saw, heard, or did. Witnesses can't testify to what someone else told them happened (that's hearsay), and ordinary witnesses can't give expert opinions outside the scope of common experience.