Bhagavad Gita
18.2

श्रीभगवानुवाच | काम्यानां कर्मणां न्यासं संन्यासं कवयो विदुः | सर्वकर्मफलत्यागं प्राहुस्त्यागं विचक्षणाः ||

śrī-bhagavān uvāca kāmyānāṁ karmaṇāṁ nyāsaṁ sannyāsaṁ kavayo viduḥ sarva-karma-phala-tyāgaṁ prāhus tyāgaṁ vicakṣaṇāḥ

Translation

The Blessed Lord said: The sages understand sannyasa as the giving up of actions motivated by desire; the wise declare tyaga to be the abandonment of the fruits of all actions.

Interpretation

Krishna defines both terms with precision. Sannyasa is the renunciation of desire-driven actions (kāmya karma — actions done to fulfill personal desires). Tyaga is something subtler and more radical: the abandonment of the fruits of ALL actions — not just desire-driven ones but all actions, including obligatory duty. A sannyasi renounces certain types of action; a tyagi acts fully in the world but releases attachment to results. The Gita advocates tyaga — engaged action without fruit-attachment — as the higher and more complete path for most people.