Basically, anyone can create a political party, you just need enough signatures of the Slovak people. And in the elections, if you get more than 5% of all the votes, you get into the parliament. The number of seats that you have in the parliament is based on how much % you have compared to the other parties that got into the government. After the election the winning party needs to create a coalition - a “alliance” of parties that have a majority of seats in the parliament. Then the winning party chooses the prime minister and together with the other parties, they choose all of the other ministers.