Pressure groups fight for public interests in an indirect way. They influence the government in making decisions which promote its interests. They fight and try to achieve a common objective. They do not take part in competitive politics but try to influence the government by different means. Whereas political parties take direct participation in competitive politics. They contest elections in order to win a majority and form government. Their aim is to achieve political power. They have their own ideology and have their own way of achieving their aim.