President Donald Trump has claimed that pardons signed by his predecessor Joe Biden are invalid. His reasoning: They were allegedly signed with an autopen, a signing machine used by the U.S government for decades.

Donald Trump says Joe Biden's last-minutes pardons via autopen are null and void. But what is an autopen? And what does it mean for pardons?

President Donald Trump suggested Monday that the legality of autopen-signed pardons should be decided by the courts, questioning whether former President Joe Biden’s final clemency orders, including controversial preemptive pardons,