This is the 3489th most frequent Swedish word.
da
"Da" in Swedish means "then" or "at that time."
Here, 'då' is used as a conjunction meaning 'as'.
Jag var glad, då jag visste att jag hade gjort bra ifrån mig.
I was happy, as I knew that I had done well.
In this sentence, 'då' functions as a temporal adverb meaning 'when'.
Han ringde mig då han hade en fråga.
He called me when he had a question.
In this case, 'då' serves as an adverb indicating 'then' or 'at that time'.