Lord Vishnu is the preserver of the universe in Hinduism, who appears on Earth to live with us at times. He has ten major incarnations, including Lord Rama and Lord Krishna
Vishnu, who holds a discus, a conch, a lotus, and a mace, lives on his planet (Vaikuntha) with Goddess Lakshmi, his shakti (energy) and spouse.
For most Vaishnavas, Vishnu is the Supreme Personality, and Lakshmi is the Mother Goddess. Some Hindus worship Lakshmi specifically for abundance/wealth.
Scriptures covering their divine plays include the Vishnu Purana, the Padma Purana, and the Srimad Bhagavata Purana.
While many Vaishnava Hindu saints have worshipped Laksmi-Vishnu exclusively, many have worshipped Sita-Rama or Radha-Krishna. Many have considered Rama (or Krishna) as the Supreme Being, who has incarnated as Vishnu to run the universe.