He laid it on the twisted cord, He turned the point at Lanká’s lord, And swift the limb-dividing dart Pierced the huge chest and cleft the heart, And dead he fell upon the plain Like Vritra by the Thunderer slain.

In plain words: Rama aims the arrow at Ravana, the lord of Lanka, and it pierces his chest and heart. Ravana falls dead, like the demon Vritra killed by Indra's thunderbolt.