The Heart Sutra of Prajna Paramita is the shortest of all the sutras, only 260 characters in the Chinese translation. However, the sutra explains the core teaching of Buddhism — Emptiness. The realization of nothingness is not a negative zero-ness. It conveys the importance of not attached to anything, especially one’s own perceptions, judgements, feelings, desires etc. The Heart Sutra is very profound and hard to understand, and one can always get better understanding as one keeps observing and practicing it.