Complex sentence: Proportional representation (PR) is a principle applied to voting systems to elect an assembly or council to ensure that the number of seats won by a party or group of candidates is proportionate to the number of votes received.
Split into simpler sentences: Proportional representation (PR) is a concept in voting systems used to elect an assembly or council. PR means that the number of seats won by a party or group of candidates is proportionate to the number of votes received.