What does Genesis 3:4 mean?

Now the serpent was more subtle than any animal of the field which Yahweh God had made. He said to the woman, “Has God really said, ‘You shall not eat of any tree of the garden?’”

The woman said to the serpent, “We may eat fruit from the trees of the garden,

but not the fruit of the tree which is in the middle of the garden. God has said, ‘You shall not eat of it. You shall not touch it, lest you die.’”

for God knows that in the day you eat it, your eyes will be opened, and you will be like God, knowing good and evil.”

When the woman saw that the tree was good for food, and that it was a delight to the eyes, and that the tree was to be desired to make one wise, she took some of its fruit, and ate; and she gave some to her husband with her, and he ate it, too.

Their eyes were opened, and they both knew that they were naked. They sewed fig leaves together, and made coverings for themselves.