The Tolkien character known as Strider before his royal identity is revealed is Aragorn. He first appears in The Fellowship of the Ring as a mysterious ranger who offers protection to the hobbits at Bree.
Strider is a nickname associated with Aragorn’s years of wandering in the wild. He is also known by names including Thorongil and Estel, reflecting different periods and purposes in his life. His ancestry traces back to Isildur, making him an heir of the kings of both Arnor and Gondor.
As the story progresses, Aragorn becomes a central leader in the resistance to Sauron. He accepts the responsibilities of kingship and is crowned King Elessar after the War of the Ring. Strider is sometimes mistaken for a separate character, but it is one of Aragorn’s identities, used to conceal his heritage while he serves as a ranger.