Unconditional Election.

Election is those chosen by God to be Saints. The term Predestined is also used, with (as far as I can tell) identical meaning.
It remains to be seen whether Election/Predestination is eniterly equal to Salvation, or whether it is possible to be elected to be a saint, and yet fail to qualify for Salvation. That is the issue of the Perseverance of the Saints.
Unconditional is meant by Calvin to mean not based in any good works, past or future, and not based on any human merit.

Firstly, you need to know, that like Luther, cited above, Calvin was a complete determinist, and this informs his view of election and predestination. For example, Calvin writes,'By predestination we mean the eternal decree of God, by which he
determined with himself whatever he wished to happen with regard to every man. All are not created on equal terms, but some are preordained to eternal life, others to eternal damnation; and, accordingly, as each has been created for one or other of these ends, we say that he has been predestinated to life or to death.'
Book 2, chap 21, sect. 5.

So not only is Election Unconditional, that is not based on works, it is also predestined not only without regard to anything you might do or not do in your life, but it is based on the premiss that you cannot do anything other than the will of God. Luther writes something similar, 'For if we believe it to be true, that God fore-knows and fore-ordains all things; that He can be neither deceived nor hindered in His Prescience and Predestination; and that nothing can take place but according to His Will, (which reason herself is compelled to confess;) then, even according to the testimony of reason herself, there can be no "Free-will" - in man, - in angel, - or in any creature!' (Luther, 'Bondage of the Will' Conclusion, Sect 167.)

The consequence of this is two fold. Firstly, there is no relationship between one's life as a Christian and salvation. You were chosen to be saved, and all you do is determined by God, and you were not chosen on the basis of anything you have done or would do in the future. To support the claim that election is not conditional on works, as well as many arguments, Calvin cites Timothy, "Who has called us with a holy calling, not according to our works, but according to his own purpose and grace,
which was given us in Christ Jesus before the world began," (1 Tim. 2: 9.)

The second consequence is what is known as double predestination. If God has predistined all those who will achieve salvation, then God has by omission predestined everyone else to damnation. Calvin freely admits as much in the passage above from chap. 21 sect 5 '...some are preordained to eternal life, others to eternal damnation; and, accordingly, as each has been created for one or other of these ends, we say that he has been predestinated to life or to death.'

Now, what Calvin has failed to elaborate is this: If the Saints are elected to Salvation, not on the basis of works, but unconditionally, then those who are predestined to damnation are also predestined unconditionally, not on the basis of works. Calvin can claim that sinners are damned because of their sin. But in reality, there are sinners in heaven and hell, and there is no condition, certainly not works, that allows one to distinguish between them. So as far as we can tell it is random chance who goes to heaven and who to hell.

But this leads us onto the next point of TULIP - Limited Atonement. If Christ died to save the world, why is only the elect, and not the world saved?