In political systems, a "third party" refers to any political party outside the two major parties typically dominating the political landscape, such as the Democrats and Republicans in the United States. These parties often arise to represent specific interests, ideologies, or demographics not adequately addressed by the main parties. The presence of third parties can influence election outcomes, lead to shifts in political discourse, and introduce new policy ideas. However, third parties often face challenges like ballot access and funding limitations, making it difficult to compete on equal footing with established parties.