US presidential politics has a language all its own. Here are some words that crop up regularly in the campaign:

Nominating Convention — The party's candidate for the November election is selected at a gathering of party representatives. The person who gets the majority of their votes is considered the nominee to face the other party in the general election. This year the Democratic convention will be held in Denver on Aug 25-28 and Republicans gather in Minneapolis-St Paul on Sept 1-4.

Delegates — They are the ones who attend the conventions and select the winner. They are selected to represent all 50 states and also the US territories.

Primary — The manner in which many of the delegates are selected. Voters go to the polls and cast ballots for their favourite candidate. Each state has different rules. Many primaries allocate delegates based on the percentage of the vote that the candidate gets, although some give all the state's delegates to the person who ends up on top. Some primaries are limited to political party members while others are open to independents and sometimes the other party.

Caucus — Another way to pick delegates. This selection process involves the party faithful gathering at sites around the state to negotiate and divide up the allotted number of convention delegates. The process varies from state to state and can be a tiny meeting of party insiders or big events like those in Iowa that attract media coverage from around the world.

Super Delegates — A certain amount of delegates at the conventions are set aside to be members of Congress, elected state officers and other leading party officials. They are not picked by primary or caucus and are not committed to any particular candidate, therefore they can back anyone they want.

Presumptive Nominee — Often each party's nominee is clear well before the conventions. But the process has to be formalised with a vote, so until they are, candidates are called the presumptive nominee. In the case of the Democrats, the winning candidate has to secure a simple majority of 2,025 votes by delegates and super delegates at the convention, while the Republican candidate has to secure 1,191 votes.—Reuters