The literature of political science abounds in terms that denote an aggregate of individuals interest group, social or political movement, pressure group, organized interest, pany and so on.
Some of these terms are used almost interchangeably, others have a very specific meaning. An interest is a desive for, or concern over, either an abstract or a material political object. According to this definition, then, persons who want the government to deliver mail twice instead of once a day, have political interests. The object of desire differs, to be sure, nevertheless, each can be characterized as political.
when consensus does not exist over the acquisition of a particular political good conflict occurs and the acquisition of that good becomes an issue. Interest groups are associations of individuals who share a desire for a contested political good In the most general sense, an interest group can be defined as a goal seeking social aggregate.
To qualify as an interest group, a social aggregate must have as its goal some political objective which its members are incapable of obtaining by virtue of any formal political positions they may hold either individually or collectively.