Puja means I call you and offer you some respectable [indistinct], some foodstuff, and then very much seated very comfortably. Naturally I may ask, "What do you want?" Then I'll expect, "Give me this. Give me that. Give me that." That is going on. That is called puja. But those who are worshiping the Supreme Personality of Godhead, that is not called puja; that is called seva, krsna-seva. We never say krsna-puja. Nobody… Never says like that. Seva. Seva means it is my duty. I am eternal servant of Krsna. Seva is my duty. So there is difference between puja and seva. Puja means I flatter you to satisfy you, and after being satisfied, you may offer me something, or I'll ask you something and you offer me. That is called puja. That is devata-puja. But, so when you come to Krsna, or Visnu, that is not puja; that is seva. Seva. So as Krsna is offered seva, service, similarly His representative, he is also offered seva.

From Srila Prabhupada's lecture on Srimad-Bhagavatam 5.5.1 — October 22, 1976, Vrndavana