This is the 10054th most frequent Russian word.
аукциона
"Аукциона" means "auction."
The word 'аукционе' is used in the prepositional case to indicate the setting of being involved in the auction.
Он подробно рассказал о правилах участия в аукционе.
He explained in detail the rules for participating in the auction.
The word 'аукцион' is used in the nominative case to indicate the subject of the sentence.
Аукцион начнётся в пять часов вечера.
The auction will start at five o'clock in the evening.
The word 'аукционе' is again used in the prepositional case to indicate the location or setting of where an action took place.