The mantra is only the Sanskrit syllables, not translation as it falls under on one of the Five Categories of Untranslated Terms. As the mantra is a secret language of Buddha and Bodhisattva its meaning is mystical. People who uphold the mantra by reciting it will have inconceivable responses and effects.
However, the brief "meaning" of the mantra is as follows:
End of Heart Sutra Commentaries