Faramir is the younger son of Steward Denethor II of Gondor, and a seemingly less masterful man than his hardier brother Boromir. Yet he inspires more trust and loyalty, and he is instrumental in helping Frodo and Sam on their quest to Mordor.
He understands about the Ring, and yet has no desire for it: "Not even if I found this thing on the side of the road ..."
When his men encounter Frodo trespassing in Gondor during a battle, Faramir was bound by the king's command to execute him on the spot. Yet he took counsel in this "hard matter" and decided to grant them clemency on his own responsibility. He risked his life to do this, for to disobey the king was considered treason.
Faramir took Frodo and his trusty servant-companion Sam to his secret fortress, with the gentlest of constraints, insisting only that the pair be blindfolded. There, he hears Frodo's tale in detail, supplies him with food and drink, and escorts him to the border of Mordor. He even allows Frodo to take Gollum under his protection.
The movie version portrays Faramir as desirous of the Ring, one of several distortions of the original story. (This might be the reason Tolkien's son ended his consulting relationship with the movie director - see Christopher Tolkien).