For Italians 'confetti' are not what you throw in the air at parties – those are called 'coriandoli'. In Italy, confetti are candy-covered almonds that Italians give out at weddings. They put an odd number of them in a little sack and tie it to a wedding favor for each guest to take home. They also put a little tag inside the sack with the bride and groom's name and the wedding date on it.

This wedding tradition dates back to Roman times when almonds were honey-coated (no sugar until the 1400's) and given out at weddings and baptisms.
In Byzantine Venice, confetti were tossed off balconies during carneval parades (auth: maybe this is where the mix up started between confetti and coriandoli).
The number of candies in each sack is usually five and must always be an odd number, symbolizing the indivisible nature of marriage.