A behind-the-scenes look at what actually goes on during an IPO on the New York Stock Exchange

IPOs occur when companies offer their stock, or shares of the firm, to the public for the first time.

There are a few exchanges in the US on which stocks are traded, and thus IPOs can take place.

The New York Stock Exchange is the largest and oldest of these exchanges, dating from 1792, and it sits in its iconic home on Wall Street.

Business Insider got a backstage look at one of the IPO days through the eyes of Carolyn Saacke, the chief operating officer for NYSE's capital-markets business. The capital-markets business oversees all IPOs and maintains relationships with the firms that are already listed on the NYSE.

Here's a backstage look at the wild day of an IPO: