Voters fill out their ballots at a polling station in Brooklyn, New York on Nov. 5, 2013

With the midterm elections less than three weeks away, we figured it would be helpful to step back and address a few simple questions. For that, we turn to Shushannah Walshe, deputy political director for ABC News and co-author of "Sarah From Alaska: The Sudden Rise and Brutal Education of a New Conservative Candidate." Walshe has also consulted for the HBO show "The Newsroom."

1] So, let's start with the basics. For those who don't know or have been too busy watching the new season of "Homeland" or reading "Gone Girl" think pieces: what are the midterm elections and when are they? Sometime next month, right?

SW: Yes, on Tuesday, November 4. But, are you too busy? Aren't we all? In many states there is no need to wait to vote. You can vote early-in many states you can even go today. We are less than three weeks away and according to early voting expert Michael McDonald with the United States Election Project over 1.6 million Americans have already voted. In every district, wherever you live, you can find that information easily accessible online. So, what are you waiting for? Ah maybe you like the excitement of waiting until Election Day.

Now to the big question: what are the midterm elections? Midterm elections happen halfway through the president's four-year term and if you are wondering if you can vote or should, well that answer is yes, if you are registered. That's because every member of the House of Representatives is up for re-election, yes yours! That's not all. There are important Senate and gubernatorial races as well. What's the most important? Well, it's all important, but we are closely watching whether the Democrats hold on to the Senate or not (more on that below). Republicans need to gain six states in order to do that and there are several tight races-some that may not even be decided until after Election Day--making it impossible to know right now what will happen.

2] Ok, so - as much as everyone is talking about Hillary Clinton - the White House is not actually in play this year. How many seats in the Senate and House of Representatives are up for grabs? A number of governors' races are happening as well right?

SW: Correct, the president has two more years and the next POTUS will be elected in 2016. When will that race start? Oh about a day after the midterms are over. But, let's concentrate on this election. All 435 members in the House of Representatives are up because they are up for re-election every two years (what a grind!) and there are 36 gubernatorial and 36 Senate races. Sixteen of those Senate races are deemed competitive by ABC News ratings and of those 16, five are toss-ups. Of the governor's races our ratings show 21 are competitive with seven toss-ups. Go to ABCNews.com's 14 for 14 coverage to see if any of these hot races are in your state.

3] So the House is currently controlled by the Republicans AKA the GOP. The Senate is controlled by the Democrats. Any clue if either body will change hands?

SW: We don't believe the House will change hands, meaning Republicans will stay in control of the lower chamber. Republicans are actually hoping to gain even more seats next month, while Democrats are aggressively trying to prevent that from happening. There aren't really that many toss-ups despite every seat being up and just a relatively small number that the campaign committees pour money into and watch closely because they tend to flip back and forth between the parties.

But, the real fight to watch on November 4 is whether the Senate changes hands from the Democrats to the Republicans. You may be seeing all those nasty ads at home on your TV and this is likely why, because we are in the last weeks of a death match and Democrats are trying to hold control and the GOP wants to wrest it from them, knowing it's only six seats that could make a difference. It all depends on just a handful of critical races; see below for more on that.

If you are interested in paying attention these final weeks those are the exciting races to watch, with all of them it could be that one race that determines control. What happens if there is a tie? A tie means that the Democrats win because Vice President Joe Biden is actually the tie breaker. Currently Nate Silver and his team at FiveThirtyEight give Republicans a 60.8 percent chance of taking control of the Senate and give Democrats a 39.2 percent chance of keeping the majority.

4] OK, so let's say the Republicans win the Senate. What does that actually **mean** in real terms? What will change in Washington?

SW: There's so much gridlock now, how could there be more? But, yes expect more gridlock because the president, a Democrat, will still be in the White House while Republicans will hold Congress. It's quite likely even less could get done. It would shift, though. Instead of Congress not getting anything done, the president will likely veto more of what Congress passes.

Of course, Republicans could worry again about more primary challenges so any lawmaking may come to a grinding halt. Many Republicans and Democrats running now are promising to work across the aisle, trying to sell themselves to a public that is sick of congressional fighting. If those promises are true then maybe all these predictions will be wrong, but don't bet on it. It's not just voters that are sick of the inaction; there are plenty of senior legislators who are sick of it too. Maybe they will get their way and come to a truce of sorts. Again, unlikely. One other possibility is that President Obama moves toward the Republicans to try and get something-anything-done. We'll be watching.

5] So, we established there are a lot of races happening. Can you name three races you find most compelling and why?

SW: There are a lot of races and narrowing it down to three is difficult, but let's give it a try. The Georgia Senate race has just recently become a toss-up and it's all because of an outsourcing controversy that has hit the Republican in the race, businessman David Perdue, pretty hard. He's running against Michelle Nunn, daughter of former Georgia Sen. Sam Nunn, and for months it looked impossible for a Democrat in red Georgia to win, but now it's likely to stay tight until Election Day.

Another exciting, and also somewhat unexpected battle, is the Kansas Senate race. In that fight, three-term incumbent Pat Roberts is battling it out against independent Greg Orman. Kansas is also a bright red state, a place not really accustomed to competitive elections never mind this brawl. Orman says he's an independent choice, while Roberts and his allies are trying to label with him with the L word, liberal. Kansas also has an exciting gubernatorial race, but I won't count that as my number three.

For my final one, let's go with a governor's race. The Florida governor's race is a fascinating one pitting the Republican incumbent against the former GOP governor of the Sunshine State, Charlie Crist. Crist is back, but this time he's a Democrat, and everywhere he goes he's accompanied by a fan. Yes, a fan. As a Floridian, I can attest that it gets hot at home, but this fan has even impacted the race with Scott refusing to come out to their debate Wednesday because of the fan. Yes, fangate.

For more on all of these races, as well as to watch all the race calls on election night, make sure to stay with ABCNews.com.

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