Jīvātmā — The Individual Soul in Viśiṣṭādvaita
Jīvātmā (Sanskrit: jīva = living being + ātmā = self/soul) refers to the individual conscious self — the real 'I' that underlies the body, mind, and senses, and persists through birth, death, and liberation. In Viśiṣṭādvaita Vedānta, the jīvātmā is real, eternal, and conscious (cit), but it is not identical to Brahman (Bhagavān). Rather, it stands in the relation of viśeṣaṇa (qualifier/mode) to Bhagavān as the viśeṣya (substance), which is the meaning of the doctrine of śarīra-ātma-bhāva — the jīvas and the universe constitute Bhagavān's body.
Distinction from Body and from Paramātmā: The jīvātmā is atomic in size (aṇu), self-luminous, and distinct from the gross and subtle bodies it inhabits through saṃsāra. It is also distinct from Paramātmā (Bhagavān Himself as the antaryāmī dwelling within all beings), though inseparable from Him. This is the Viśiṣṭādvaita resolution: jīvātmā and Paramātmā are not one (as in Advaita) nor fully separate (as in Dvaita), but related as body to soul, part to whole, śeṣa to śeṣī.
The Praṇavam and the Jīvātmā: Piḷḷai Lokāchārya, in Mumukṣuppati, teaches that the praṇavam (Om) encodes the jīvātmā's essential nature in its first syllable a: the akāra denotes that the jīva is aṇu (atomic), cit (conscious), and ananya-śeṣa (exclusively belonging to Bhagavān). The ukāra confirms the exclusive nature of this relation: the jīva belongs only to Bhagavān. The makāra declares that Bhagavān is the jīva's ultimate puruṣārtham (goal). Thus the entire upaniṣadic message about the ātmā is compressed into a single syllable.
Bound, Liberated, and Eternal: Jīvātmās are classified as baddha (bound in saṃsāra), mukta (liberated and dwelling in Śrī Vaikuṇṭham), and nitya (eternally free souls who have never been in saṃsāra, like Ādiśeṣa and Garuḍa). Nammāzhvār's Tiruvāymozhi is the supreme poetic expression of the baddha-jīva's longing and eventual liberation through Bhagavān's grace — the entire Prabandham is the cry of the jīvātmā recognising its true nature.