Guidance (هُدى) is one of the most important themes in the Quran. We ask for it 17+ times daily in prayer!
From root ه-د-ي:
- هَدَى (hadā) = he guided
- هُدى (hudā) = guidance
- اهْدِنَا (ihdinā) = guide us
- مُهْتَدٍ (muhtadī) = rightly guided
The opposite is ضَلَال (ḍalāl) - going astray.