https://youtu.be/Ds68Dm3CBTU?si=iL4LG5QQM03G-UIe The bible tells us in the book of Genesis 6 :4, that there were giants in the earth in those days and also after that when the son's of God came in unto the daughter's of men and they bare children to them, the same became mighty men which were of old men of renown.
The giants in this verse are the Nephilim, described as mighty men of old. They are the offspring of a union between the son's of God and women of the world. The word Nephilim can also be known as fallen ones but they were referred as the mighty men in the bible. They are also known as divine being who rebelled against God by leaving their heavenly place and take human wives.
They were born from unnatural union. You can call them heroes of old, mighty men or men of renown. They were also on earth before and after the son's of God. The presence of the giants also caused the increase of the corruption of human race.