Political parties are groups that contest elections to promote policies and programs for society. They have leaders, members, and supporters. Major functions of parties include forming governments, making laws, and shaping public opinion. Party systems can be one party, two party, or multi party depending on how many parties can realistically win power. In India, major national parties include the Indian National Congress, Bharatiya Janata Party, Bahujan Samaj Party, and Communist Party of India (Marxist). Challenges facing parties include a lack of internal democracy and connection to money and business interests. Reforms proposed include limiting defections and increasing transparency and women's representation.