(CNN) -- Election night can be as confusing as it is exciting. What's the difference between electoral votes and popular votes? What's a balance of power? Read through our glossary to learn more about these and other terms.

Balance of power: The party with the most seats in each of the two houses of Congress -- the House of Representatives and Senate -- controls the leadership of that house. The balance of power shows which party has the most seats, how many seats are up for election this year and how many each party has won on election night according to CNN projections.

Ballot measures: State authorities place a wide variety of questions on the ballot for voters to decide. Although the questions vary widely, they often will determine the fate of proposed changes to state tax laws or changes to state constitutions.

Battleground state: A state where voter support is nearly equally divided between major party candidates and either candidate could win.

Blue state: Traditionally, a Democratic-controlled state or a state that has voted for the Democratic presidential candidate.

Electoral votes: It takes 270 electoral votes to win the presidency. Voters are deciding which presidential candidate gets each state's electoral votes. Most states are winner-take-all. Each state's electoral vote equals the number of senators and representatives and is allocated based on population.

Exit polls: On Election Day, news organizations and other groups dispatch pollsters to polling places. Pollsters ask voters to reveal who they cast their ballots for and why. Pollsters use this data to make early guesses about which candidates will win and to determine which groups of voters tended to support certain candidates.

GOP: Grand Old Party, nickname of the Republican Party.

House seats: Every two years, all 435 seats in the U.S. House of Representatives are up for election by popular vote in each member's local voting district. The number of House districts in each state is determined by the state's population in the most recent U.S. census, which occurs every 10 years.

States with more citizens are allocated more representatives among the 435 House members. The nation's most populous state, California, has the most House members: 53. Six states with small populations each have just one House representative. Each district's geographic boundaries are determined by authorities in each state.

Percentage of precincts reporting: Each voting precinct must report its local results to a central authority before an official winner can be determined. This number is displayed by county and state for president, Senate, governor and ballot measure contests, and by county and district for House races.

Popular vote: The total number of votes cast for each candidate by all voters. In 2000, George W. Bush did not win the national popular vote, although he did win enough electoral votes to win the presidency.

Red state: Traditionally, a Republican-controlled state or a state that has voted for the Republican presidential candidate.

Senate seats: Each state has two Senate seats and Senate elections are staggered. Every two years, one-third of all 100 Senate seats are up for election. A Senate term is six years.