A Sampradaya is the name given to a Spiritual succession or lineage within a particular Hindu denomination.
To receive initiation (Diksha) into a Parampara or Guru lineage allows one to be officially made a member of that Sampradaya to which his or her guru lineage belongs.
Each Sampradaya has its own spiritual lineage, philosophy, monastic communities, literature, pilgrimage places and temples etc although sharing a wealth of heritage, culture and belief with other schools which under a Sect they find their greater expression of tradition and ideologies.
In order to help elucidate the concept of Sampradaya there are four main denominations within the Hindu Religion:
Vaishnavism - who worship the Supreme God as Vishnu (also called Narayana)
Shaivism - who worship the Supreme God as Lord Shiva (also spelt Siva)
Saktism - who worship the Supreme as the Divine Mother, Sakti or Devi.
Smartism - Liberal Hindus who worship all other Hindu Gods as valid manifestations of the Divine.
Within each denomination there are numerous sub-sects or schools called Sampradayas.
Within Vaishnavism these Sampradayas include:
Sri Vaishnavism Sampradaya - Whose members adhere to the teachings and lineage of Ramanuja
Dvaita or Brahma Sampradaya - who follow Madhva
Ramanandi Sampradaya - Who follow Ramananda
Sri Swaminarayan Sampradaya - who follow Swaminarayan
Pushtimarg Sampradaya (Rudra Sampradaya) - who follow Vallabhacharya
Kumara Sampradaya - who follow Nimbaraka
Gaudiya Vaishnavism (which includes the International Society for Krishna Consciousness or Hare Krishna Movement) - follow Chaitanya Mahaprabhu
Mahapuruxiya Dharma (Asomiya Vaishnavism) - follow Srimata Sankaradev
Krishna Pranami Sampradaya - follow Devachandra Maharaj
Within Shaivism these are six main schools or Sampradayas:
Saiva Siddhanta - follow Tirmular (Sundaranatha) or Meykanadev depending upon the specific school ie Nandinatha Sampradaya (Monistic school) and Meykandar Sampradaya(Dualistic school).
Adinath Sampradaya (Siddha Sampradaya) - follow Gorakhnath and Matsyendranath
Siva Advaita - follow Nilakantha and Appayya Dikshitar
Kashmir Shaivism - follow Vasugupta and his disciplic lineage
Pasupata Shaivism (Pasupatism)- follow Lakulisa
Veera Shaivism (Vira Shavism)- follow Basavanna
Within Saktism and Smartism there are numerous sects, organisations and groups throughout the world although not officially reffered to as Sampradayas.