A political party differs from an interest group in that

A political party differs from an interest group in that it does not participate in elections.

Political parties are groups that: share common social and political ideas; organize to win local, state, and/or national elections to take governmental control. Interests groups organize with the intent of reaching out to policymakers and influencing their decisions. Interest groups do not run a candidate for political office and can represent large businesses, corporations, social groups, occupations, and labor unions.