What it means
Discovery is the pre-trial process where parties disclose to each other the documents relevant to the dispute that are in their possession or control. The duty extends to documents that hurt your own case, not just those that help it. The documents are usually listed and then made available for inspection. Discovery promotes fairness by reducing surprise and helping both sides assess the strength of the case.
How it's used
During discovery the company had to produce internal emails that contradicted its defence.