Two definitions

śrībhagavānuvācakāmyānāṃ karmaṇāṃ nyāsaṃ saṃnyāsaṃ kavayo viduḥsarvakarmaphalatyāgaṃ prāhustyāgaṃ vicakṣaṇāḥ

The wise call giving up desire-driven actions renunciation. The discerning call letting go of craving for the fruit of every action relinquishment.

What it means

Krishna gives two definitions. Sannyasa, renunciation, is dropping actions done only to satisfy desire. Tyaga, relinquishment, is letting go of craving for the fruits of every action, while still doing them. One stops certain actions. The other keeps acting, without clinging to results. Krishna will favour the second.

The story

Arjuna wanted to drop his duty altogether. Krishna offers the deeper option. Keep doing your duty, but release your grip on how it turns out.

In your life

Imagine a parent who keeps helping their adult child, but stops needing them to make the choices the parent wants. That's tyaga. Help someone today without needing a particular result.