This is a reference to the world of the Roman Empire.
This is a reference to all the people of Judea.
This should not be taken out of context. At this particular time, the Lord was focused on His apostles, and that they would remain unshaken while He was crucified, and then would depart for Heaven. See the context.
So what exactly does this mean? Does it mean that God elected some for salvation, and others for damnation, or that God -- IN HIS DIVINE FOREKNOWLEDGE -- knew who would obey the Gospel, and would therefore be appointed to receive eternal life? Since Scripture cannot contradict itself, and Christians are elected according to foreknowledge (1 Pet 1:2), there is no conflict between divine foreknowledge and obedience to the Gospel
Strong's Concordance
tassó: to draw up in order, arrange
Original Word: τάσσω
Part of Speech: Verb
Transliteration: tassó
Phonetic Spelling: (tas'-so)
Short Definition: I assign, arrange
Definition: (a) I assign, arrange, (b) I determine; mid:
I appoint.
But when we come to the finished work of Christ, it is an entirely different matter. And even the lexicons confirm that Jesus is speaking about all the inhabitants of the earth in John 3:17:
For God sent not his Son into the world to condemn the world; but that the world through him might be saved.
To "condemn the world" can mean nothing other than the whole world of humanity (since all have sinned and come short of the glory of God). Therefore "the world (Gk kosmos) through Him might be saved" can also mean nothing less than the whole world of humanity.
Strong's Concordance
kosmos: order, the world
Original Word: κόσμος, ου, ὁ
Part of Speech: Noun, Masculine
Transliteration: kosmos
Phonetic Spelling: (kos'-mos)
Short Definition: the world, universe
Definition: the world, universe; worldly affairs; the inhabitants of the world; adornment.
Thayer's Greek Lexicon
STRONGS NT 2889: κόσμος
κόσμος, κόσμου, ὁ;
5.
the inhabitants of the world:
θέατρονἐγενήθημεν τῷ κόσμῳ καί ἀγγέλοις καίἀνθρώποις,
1 Corinthians 4:9 (Winers Grammar, 127 (121));
particularly the inhabitants of the earth, men, the human race...
John 3:17;
John 10:36;
John 17:18;
1 John 4:9;
As thou hast sent me into the world, even so have I also sent them into the world. (John 17:18)