According to Srimad Bhagavatam Canto-7, Hiranyakashyapu’s young son, Prahallada have recently started his education at the Gurukula. So, the father asks his son, to share his thoughts on what is the best of knowledge he has learnt thus far.

Upon this request, Prahallada explains Navdha Bhakti to his father as the best thing that he knows and he had learnt it from Sage Narada Maharishi, even when Prahallada was in his mother’s womb.

As part of his reply to his father’s request, in the above shloka, Prahallada explains the 9 types of Bhakti also known as Navdha Bhakti or devotion one can have towards Vishnu (Rama or Krishna also are avatars of Vishnu).

SHRAVANAM – Listening to discourses about Lord Vishnu
KIRTANAM – Singing praises, bhajans of Lord Vishnu
SMARANAM – Thinking deeply of Lord Vishnu
PADA SEVANAM – Performing services at the lotus feet of Lord Vishnu

ARCHANAM – Offering pooja and worship with Shodasha Upachara -sixteen types of paraphernalia.
VANDANAM – Offering prayers to Lord Vishnu
DASYA – Being an absolute servant at the feet of Lord Vishnu
SAKHYA – Considering Lord Vishnu as the absolute best friend 
ATMA NIVEDANAM – Surrendering oneself completely to Lord Vishnu