Genesis 2:4:

These are the generations of the heavens and the earth when they were created, in the day that the LORD God made the earth and the heavens._(ESV)

_(BHS) אֵ֣לֶּה תֹולְדֹ֧ות הַשָּׁמַ֛יִם וְהָאָ֖רֶץ בְּהִבָּֽרְאָ֑ם בְּיֹ֗ום עֲשֹׂ֛ות יְהוָ֥ה אֱלֹהִ֖ים אֶ֥רֶץ וְשָׁמָֽיִם׃

I’m wondering what “these are the generations” refers to. Is it meant as a summary of what precedes it or as an introduction to what follows it?

I’m also not sure what תֹולְדֹ֧ות (tolədôt; ESV, “generations”) refers to in this context. Other translations use “account,” which is clearer but makes me feel like I’m not quite understanding the plural sense of
אֵ֣לֶּה תֹולְדֹ֧ות (ēlleh tolədôt) nor the connection with the basic meaning which apparently has something to do with descent/ancestry.