Oak logs are logs that are cut from the oak tree. These logs can only be used for fletching bows, they cannot be burned using the Firemaking skill.
To obtain oak logs from an oak tree, a player needs 15 woodcutting and an axe which they have the required level to use to cut it down, and will earn 37.5 Woodcut experience for doing so. If fletched, oak logs will grant 25 Fletching experience for an unstrung longbow, and 16.5 experience for an unstrung shortbow. It is possible that a player can slip their axe and not cut the tree, a higher Woodcutting level lowers the chance of this.