Runes, are enchanted pieces of rune essence. Runes can be made through the Runecrafting skill. More specifically, Law Runes are mostly used for Teleportation(see magic).

Law Runes
Use: Teleportation, Magic
Grand Exchange price: 293-325gp
Examine Information:used for teleport spells
Notable features: The most expensive rune for f2p players.

Odd Uses: teleport block or tele-other spells