Testimony is a formal statement someone makes about what they know, especially in a courtroom or official setting. When a witness gives testimony during a trial, they tell the judge and jury what they saw, heard, or experienced that relates to the case. The witness stands or sits in a special place called the witness stand and answers questions under oath, meaning they've promised to tell the truth.

In court, testimony helps judges and juries figure out what really happened. A person who saw a car accident might give testimony about which driver ran the red light. A scientist might offer expert testimony explaining complicated evidence. Police officers give testimony about crimes they investigated.

Outside of courtrooms, people use the word more broadly. Someone might say that a student's improved grades are testimony to their hard work, meaning the grades prove or demonstrate that hard work. A beautifully maintained garden serves as testimony to a gardener's dedication and skill.

The person giving testimony is called a witness, and the act of testifying means giving that formal statement. False testimony, called perjury, is a serious crime because the justice system depends on people telling the truth.