what is a party system?

Answer 1

a party system is a group of people(politicians) who share the same ideas or agree on issues..

in the U.S., we have 2 major parties, Republican and Democrat
and whenever there is an election, there can only be one person from each party to represent their own party

hope this makes sense

Answer 2

This site has a great explanation of the party system:

http://en.wikipedia.org/wiki/Political_party