It's not all about confetti and balloons. Every four years, each political party meets and chooses a platform and a president -- or at least a nominee.

Most Americans see them in short bursts on TV, especially on the last night, when the nominees give their big speeches. But a lot happens before that -- and only some of it shows up on prime-time.

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Delegates get the behind-the-scenes work done: about 2,500 at the Republican National Convention and about 4,700 at the Democratic convention. They help with the party platform -- basically a document that says what the party believes, like a $15 minimum wage or renegotiating trade policies. A committee writes it up, then the delegates vote to approve or amend.

But day one is also about setting the tone in the keynote speech -- often given by a rising star in the party.

The next day, those same delegates vote again -- this time it's to decide the nominee, and it gets a lot more TV time than the day before.

Day three is all about the speakers. The party brings out its best and brightest -- at least the ones willing to speak positively about the nominee. The night is typically topped off with a speech from the candidate for vice president.

On the convention's last day, the nominee -- the party's new standard bearer -- makes their closing speech and sets their sights on their opponent.