The Pensieve is the magical object that lets Harry Potter view other memories in J.K. Rowling’s books.
A Pensieve is a shallow basin used to store and examine memories. A person can extract a memory and place it in the basin, where it appears as a silvery substance. Entering the Pensieve allows someone to experience the memory as an observer.
Dumbledore uses his Pensieve to show Harry important memories about Tom Riddle, the Gaunt family, and the prophecy that connects Harry and Voldemort. These scenes provide information that Harry could not learn through ordinary conversation.
The Pensieve is different from a Remembrall, which signals that someone has forgotten something, and from a Time-Turner, which enables limited time travel. The Mirror of Erised reveals a person’s deepest desire rather than displaying stored memories.