What is the meaning of Genesis 6:4?

* The two F.O.G. Bibles & Commentary below are currently a work in progress.

The Nephilim were on the earth in those days—and afterward as well—when the sons of God had relations with the daughters of men. And they bore them children who became the mighty men of old, men of renown.

Berean Standard Bible (BSB)

The Nephilim were in the earth in those days, and also after that, when God’s sons came in to men’s daughters. They bore children to them. Those were the mighty men who were of old, men of renown.

World English Bible (WEB)

There were giants{H5303} in the earth{H776} in those days{H3117}; and also after{H310} that{H3651}, when{H834} the sons{H1121} of God{H430} came in{H935}{(H8799)} unto the daughters{H1323} of men{H120}, and they bare{H3205}{(H8804)} children to them, the same{H1992} became mighty men{H1368} which were of old{H5769}, men{H582} of renown{H8034}.

Strong's King James

The F.O.G*

The F.O.G Paraphrase

The fallen ones were in the earth in those days, and even afterwards when sons of God come in unto daughters of men, and they have borne to them—they are the heroes, who, from of old, are the men of name.

Young's Literal Translation