Which 2003 film is the second in The Matrix trilogy?

The 2003 film that is the second entry in The Matrix trilogy is The Matrix Reloaded.

Written and directed by the Wachowskis, it follows Neo, Morpheus, and Trinity as they search for the Source while Zion prepares for an attack by the machines. Keanu Reeves, Laurence Fishburne, and Carrie-Anne Moss returned from the original film, with Jada Pinkett Smith joining the main cast as Niobe.

The Matrix Reloaded is sometimes confused with The Matrix Revolutions because both sequels were filmed together and released in 2003. Reloaded came first, premiering in May; Revolutions followed about six months later and concluded the original trilogy. The Animatrix is related to the franchise but is an anthology of animated short films, not the trilogy's second live-action chapter.