Tonight's The Big Debate TRUMP vs CLINTON

The debate will be held at Hofstra University in Hempstead, N.Y. 

Moderator NBC’s Lester. This will be the "Nightly News" host's first time moderating a presidential debate. Holt faces pressure as the first moderator of the general election cycle and the challenge of wading through a likely unpredictable debate.

What topics will they cover? 

The three topics announced are “Securing America,” “America’s Direction” and “Achieving Prosperity," which signal the debate will largely hinge on questions surrounding national security and the economy. 

At least 30 minutes of the debate will be focused on national security. The debate comes in the wake of two bombings in New York and New Jersey as well as a stabbing in Minnesota. 

What are the rules? 

The debate will have six 15-minute segments, with two segments focusing on each of the three topics. Trump and Clinton will each have two minutes to respond to questions posed by Holt. 

Who is carrying it? 

The debate will air on all of the broadcast and cable news networks as well as C-SPAN, Univision and PBS. 

It will also be streamed online, and Hofstra University has provided a list of outlets that will likely stream it. 

What's the size of the debate audience? 

The debate commission won’t know the size of the audience until Monday, after the set is complete and the fire marshal signs off. A Hofstra spokeswoman estimated there will be about 1,000 people in attendance. Hofstra University students can receive tickets through a lottery system, and the parties and campaigns also get a number of tickets they can divvy out. 

What does the debate mean for Clinton and Trump? 

Shorter Clinton to get higher podium . . . Donald Trump and Hillary Clinton will have podiums of different sizes during their first presidential debate on Reports previously claimed that Clinton's campaign had requested a custom-made podium to make up for the difference in height between the two nominees. Clinton is 5'4" and Trump is 6'2". Her campaign first asked that she debate on a step-stool so as not to appear smaller than Trump. Daily Mail