What is the difference between Pind Daan and Shraddha?

Pind Daan is the act of offering rice balls (Pindas) to departed ancestors at a sacred tirtha — primarily a liberating ceremony most powerful at Gaya, Prayagraj, or Varanasi. Shraddha is a broader term for all ancestral rites performed with faith, encompassing Tarpan, Pind offerings, and Brahmin feeding. Shraddha is the annual obligation performed on the death anniversary and during Pitrupaksha; Pind Daan at a tirtha is an intensified ceremony specifically aimed at liberating the soul. Both are necessary.