What: "Brexit" is an abbreviated term that refers to Britain's possible withdrawal from the 28-nation European Union. It is an adaptation of "Grexit," a reference to a possible Greek exit from the eurozone.

When: On June 23, British voters will decide whether their country remains in the EU. The date was set by British Prime Minister David Cameron.

Referendum question: Voters will be asked, "Should the UK remain a member of the EU or leave the EU?" The question was recommended by Britain's Electoral Commission and accepted by the government and parliament.

Why: To appease the Conservative Party and undermine EU opponents, Prime Minister Cameron promised to hold a referendum on the issue if he was reelected in 2015. Conservatives, now in the majority, have been split on the question of EU membership for some 40 years. Grassroots Conservatives generally favor leaving the EU.

Significance: Proponents of a British exit believe it would free Britain from rules that are adverse to job creation and allow the country to choose its laws and trading partners. EU advocates contend Britain should maintain its membership in a bloc of like-minded countries, a move they say would help sustain the country's global influence and military and economic security.

Eligible voters: Citizens over age 18 can cast ballots on the Brexit question. This includes citizens in Britain and the Commonwealth of Nations, an intergovernmental group of 53 member states.

Outlook: Various pollsters are regularly tracking public opinion on the Brexit issue. The Economist has produced an interactive poll-tracker that tracks sentiment on a daily basis.