Bhagavad Gita · Jnana Vijnana YogaChapter 7, Shloka 14 (7.14)

Shankaracharya. Daivī devasya mama īśvarasya viṣṇoḥ svabhāva-bhūtā — belonging to the nature of the Deva — of me, Ishvara, Vishnu; duḥkhena atyayaḥ atikramaṇaṃ yasyāḥ sā duratyayā. The means: sarva-dharmān parityajya mām eva māyāvinaṃ svātma-bhūtaṃ sarvātmanā ye prapadyante te māyām etāṃ sarva-bhūta-mohinīṃ taranti … saṃsāra-bandhanāt mucyante — those who give up all dharmas (means) and take refuge wholeheartedly in me, the wielder of maya, who am their own self, cross this maya that deludes all beings and are freed from the bondage of samsara.

Acharya Ramanuja — "maya is not illusion". Mama eṣā guṇamayī sattva-rajas-tamomayī māyā yasmād daivī devena krīḍā-pravṛttena mayā eva nirmitā — this maya made of the gunas is daivī because it was made by me, the Deva, engaged in play. Then a long argument: māyā-śabda-vācyatvam āsura-rākṣasāstrādīnām iva vicitra-kārya-karatvena — it is called "maya" because it produces wondrous effects (a marvellous power), just as the weapons of the asuras are called maya (Vishnu Purana 1.19.19–20: the Sudarshana cut down Shambara's thousand mayas). Ato māyā-śabdo na mithyārtha-vācī — so the word "maya" does not denote mithya (unreal); even a magician is called "mayavi" because his mantras, herbs and so on (real means) produce the illusion. Evidence: Shvetashvatara 4.10 māyāṃ tu prakṛtiṃ vidyān māyinaṃ tu maheśvaram — maya = prakriti, the wielder of maya = Maheshvara. Its work: bhagavat-svarūpa-tirodhānaṃ sva-svarūpa-bhogyatva-buddhiḥ ca — to veil the Lord's nature and to awaken the sense that its own (nature's) form is what is to be enjoyed.

The difference (central, philosophical): Shankara — maya is Ishvara's power that shows the world's empirical form (in Advaita, mithya from the ultimate standpoint); Ramanuja — maya is real prakriti, a wondrous power, not illusion. For both the means is one: sharanagati (surrender).