Single Transferable Vote (STV)
This system was used for the first time in Scotland at the local government elections which took place on 3 May 2007.
Instead of marking a cross, voters indicate their preferences on the ballot paper by ranking the candidates in order (first, second, third etc) and may vote in this way for as many or as few of the listed candidates as they wish.
A formula is then used to calculate who is elected for each ward. Each Council ward returns either three or four councillors to represent local people.
First Past the Post (FPTP)
This voting system is used in UK Parliamentary elections. To vote under FPTP, the voter simply puts a cross on the ballot paper next to their preferred candidate. The candidate with the most votes wins.
Additional Member System (AMS)
AMS is a combination of FPTP and closed list proportional representation. This is the system used for elections to the Scottish Parliament. Electors have two votes, one for the part or individual candidate on a list and the other for a candidate in a constituency. The constituency representatives are elected under the first past the post system.
This is used to elect UK representatives to the European Parliament. Electors vote for a party list or an independent candidate. Each party's list of candidates, ranked accordingly to the party's preference, is published on the ballot paper and electors may place a single cross next to their choice. All the votes are counted and each party is allocated seats in the constituency in broadly the same proportion to the votes it has won. Those who became the party's elected representatives are those placed highest in the party's list of candidates.