入札 and 落札: participation in bidding and a winning result
Compare a city's repair tender and companies' equipment bids with winning a watch or a painting at auction. Separate participation in the competition from a successful-bid result.
Conducting a tender and participating
入札 (にゅうさつ) means bidding or a tender. 「市は橋の修理工事について入札を実施した。」 reports the city inviting bids for bridge repairs. The city's arrangement of the tender does not identify a winning company.
「複数の会社がその設備の入札に参加した。」 reports several companies participating in the equipment tender. Their participation is stated, while the winning bidder is not identified.
Winning at auction and the stated result
落札 (らくさつ) means a successful bid. 「競売で古い時計を落札しました。」 reports winning an old watch at auction. The focus is the successful-bid result rather than participation alone.
「その絵の落札が決まると、会場から拍手が起こった。」 describes applause when the painting's winning bid was decided. The decision and response are stated; payment or delivery is not.
Keep participation and winning distinct
入札 focuses on bidding or participating in a tender; 落札 focuses on the successful-bid result. Compare the city conducting a tender and companies entering it with the auction items' winning outcomes.
Several participants do not identify the winner or each company's probability. Even a winning result does not supply a price-selection rule or completed payment and delivery.
What information differs between several companies' equipment 入札 participation and the painting's 落札 decision?
Show the answer and why
The equipment example identifies participation in the competition; the painting example identifies a winning result. Participation does not establish winning, and the result does not supply price rules, probabilities, payment, or delivery.