Why do we use this term? First of all, Almond discusses the reason why the term political system is used in Comparative Politics. Formerly, political scientists used such terms as State, government, nation, etc. But these terms are limited by their legal and institutional meanings. Their use does not inform us about the roles played by these institutions in different States or countries.
The reason is that the role of such an institution as a legislature or a court, is determined not only by the formal provisions of the constitution and law, but is also influenced by the informal groups, political attitudes, and a great many interpersonal relationships. Therefore, Almond says, “If political science is to be effective in dealing with political phenomena of all kinds of societies, regardless of culture, degree of modernisation, and size, we need a more comprehensive framework of analysis.”
Now the concept of political system directs our attention to “the entire scope of political activities within a society, regardless of where in the society such activities may be located.” In other words, the use of the term “political system” is structurally and functionally more accurate and meaningful than the use of such terms as State, government or the like. These are particular terms and not universal terms like political system.
Regarding the usefulness of the concept of political system, Almond says further The principal advantage of the system concept is that it analytically differentiates the objects of study from the government, directs attention to the interaction of the system with other systems in its environment, to its own conversion characteristics, and to its maintenance and additive properties.”