Definition - What does Work Product mean?
Work product is the collection of materials that an attorney gathers in a trial preparation period. These materials include reports, notes, observations, other opinions of the attorney, etc. An attorney's work product is not subject to subpoena. It is for the attorney to use to organize his or her case. It does not constitute evidence that must be revealed as discoveries.
Justipedia explains Work Product
Work products exist because attorneys often need a way to organize all of their thoughts and prepare their arguments for a trial. For example, an attorney may keep notes every time they speak to their client. These notes could reflect the attorney's opinion about their client, the case or how an argument could be made around a specific point, etc. Such notes would be part of the attorney's work product, and would remain confidential and unable to be seen by opposing counsel.