Gods Love for a people is a trademark of His Election of them to be a separate special people for Himself, above all other people He didn't choose for Himself. This is seen by what God says of Israel of old Deut 7:6-8
6 For thou art an holy people unto the Lord thy God: the Lord thy God hath chosen thee to be a special people unto himself, above all people that are upon the face of the earth.
7 The Lord did not set his love upon you, nor choose you, because ye were more in number than any people; for ye were the fewest of all people:
8 But because the Lord loved you, and because he would keep the oath which he had sworn unto your fathers, hath the Lord brought you out with a mighty hand, and redeemed you out of the house of bondmen, from the hand of Pharaoh king of Egypt.
Gods Love is the particular characteristic for them He has Chosen, Chosen in Christ Eph 1:4
4 According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love:
So the World God Loves in Jn 3:16 are the people whom He set His Love upon that He has chosen for Himself [denoting a special people above all others] in Christ before the foundation of the world.
Gods Love for a people also manifests His Sovereignty over the objects of His Love, like stated in Rom 9:13
13 As it is written, Jacob have I loved, but Esau have I hated.
Again Mal 1:1-3
The burden of the word of the Lord to Israel by Malachi.
2 I have loved you, saith the Lord. Yet ye say, Wherein hast thou loved us? Was not Esau Jacob's brother? saith the Lord: yet I loved Jacob,
3 And I hated Esau, and laid his mountains and his heritage waste for the dragons of the wilderness.
Gods Love for a people distinguishes them from people He hates, whom He does not Love, so His Love is Sovereign and discriminate. 21