Moksha is a Sanskrit word meaning liberation or release from illusion. It is freedom from the cycle of birth and death, or samsara.
Moksha is achieved through the identification of your true Self or the true nature of reality, and can be gained through many different practices or paths, such as devotion or service to God, or attainment of mystical awareness. In Hinduism, it is the liberated state of the individual soul, or self-realisation.
Moksha doesn’t mean liberation from life into death and a move away from physical existence into a heavenly afterlife. In Advaita the world and our perception of it are seen as illusory, but once reality is seen as it is, freedom is attained right here in this world.