Hint: When a group of people of either same ideology or otherwise come together, organize themselves and aspire to get elected through elections we can call this assembly of that group of people as a political party. In a democracy the existence of a political party makes the system more representative of the needs and aspirations of its citizens.
Around a hundred years ago, only a few countries had a government which is democratic in nature. The most common forms of government that existed during that time are monarchy, dictatorship, theocracy etc. As the freedom struggle and dec medallionation occurred, there was a gradual rise in the number of countries adopting the democratic form of government.
When the government of a country becomes democratic in nature, then comes the need for the political parties as they work to promote the national interest and the welfare of all the citizens of a country. In Democratic states, there are a lot of diverse sets of parties - conservative parties, reactionary parties, radical parties, etc.
As we grow in a democratic system, there arises the need for more and more political parties to represent every section of society and to ensure equal justice and equal opportunity for all. A country has a diverse section of population with diverse and unique requirements and needs to fulfill the needs and requirements of all the sections of the society and to secure all the communities equally in the government system. Thus, there arises the need for a number of political parties.
As a society grows more diverse, more populous and complex, there grows the demand from different sections in terms of protest, movements and revolts which in turn takes the shape of political parties.
Note: There are three kinds of party systems that are seen in different countries. They are a one-party system, two party system and multi-party system. We can say that the number of political parties in a country is more representative of the country than for its citizens.