In J.R.R. Tolkien’s The Lord of the Rings, Aragorn is called Strider at the Prancing Pony. The name is a nickname used for the Ranger whom Frodo and his companions meet in Bree.
Frodo initially distrusts the weathered stranger because of his appearance and reputation. After Gandalf’s letter identifies him as a friend, the hobbits accept his help. Strider guides them from Bree toward Rivendell and protects them during the journey, including the attack on Weathertop.
Strider is only one of Aragorn’s names. He is also known as Elessar after becoming king, and earlier he used the name Thorongil while serving in Gondor and Rohan. Aragorn is the son of Arathorn II and descends from Isildur, making him the heir to the thrones of Gondor and Arnor. The nickname “Strider” is connected to the Bree-folk’s term for the Rangers who travel the wild lands, not to Aragorn’s royal identity.