What is the Presidential Records Act, and how did Trump violate it?

At the end of the president’s administration, officials must hand over official documents — typically amounting to tens of thousands of pages — and tapes to the federal government. That can include national security briefs, handwritten notes, daily presidential logs and calendars, emails and faxes, and records. The law also requires that presidents and their staffers take “every practical step” to preserve all this.