E.g. In such a system, if a state has 50 seats and a party manages to win 24 of them (while the second place only wins 23 seats), that first party gets all 50 seats of representation.
[1] https://en.wikipedia.org/wiki/First-past-the-post_voting
To be fair: My comment is mostly focused upon "Western" parliments, which includes two geographically non-Western places: Australia and New Zealand! If you look at the constant dominance of the Liberal Democratic Party (LDP) in Japan... look _very_ closely... you realise there are many competing factions within the party. So LDP _acts_ like multiple parties and forces the Prime Minister to compromise to get things done. Not perfect, but many outsiders fail to understand this about the Japanese (national) political system.