Step 1: Think of a political party as doing several jobs at once.
Rather than listing definitions, it helps to walk through what a party actually does from election day right up to running the country.
Step 2: Before and during elections.
Parties pick and put forward candidates for us to vote on, and they release manifestos setting out their plans on jobs, education and development, which helps voters compare choices, for example BJP, INC and AAP all do this at election time.
Step 3: After winning or losing.
The winning party or alliance forms the government, appoints ministers and runs the administration, while the parties that lose become the opposition, questioning government decisions and keeping it accountable.
Step 4: Between elections too.
Parties also keep in touch with people through rallies and campaigns, shaping public opinion and carrying people's concerns to the government, which is what keeps democracy running smoothly day to day.