Moksha is the term Hindus use for liberation from the world. For the non-dualist (Advaita), it refers to the realization of our oneness with the Absolute or our merger with God. In Vaishnava thought, it usually involves residence with the Lord on his planet in a state of complete bliss.
We can also understand the concept of moksha through its relationship with karma. When our karma no longer create karmic impressions (samskar) in our mind or when we are no longer accountable for our karma, we can say that moksha or mukti has been achieved. Because all karma derive their functioning from a combination of the three gunas of nature and no one in the perceptible universe is supposed to escape the three gunas, any soul outside the range of nature is assumed to have reached the state of emancipation. Such a soul does not have to reappear on earth.
Though moksha is the final aim of Hindu life, Sanatana Dharma gives us a disclaimer: In either route to God, the intellectual or the devotional, liberation remains as an aim of life as long as we are averted from our real nature. For the selfless devotee, who can deny even liberation for bhakti, the presence of God alone in the… mind drains away any wish for emancipation. Similarly, for the jnani, as Shankaracharya says, the concept of emancipation…is itself an ignorance-influenced imaginary concept; the distinction of being bound to the universe and being liberated rests in the intellect, not in the Absolute Reality.*
(*Text in italics is excerpted from Devotional Hinduism: Creating Impressions for God; iUniverse Inc, 2008.)