The term ‘Economics’ is taken from two Greek words, “Oikou” meaning a house and “nomos” meaning to manage. According to Greeks, economics means managing of the house hold. This definition explains how individuals are capable of using their scarce resources to manage their households so as to earn a living.

But after that, many definitions have being published. Some of which are:

1. Adam Smith (1723-1790): An inquiry into the nature and causes of the wealth of nations.
2. Alfred Marshall (1842-1884): The study of mankind in the ordinary business of life.
3. John Stuart Mill (1806-1873): The practical science of production and distribution of wealth.
4. A.C Pigou: A science of material welfare.
5. Truett: A science of how scarce resources are and can be used to satisfy human wants and needs.
6. Davenport: The science that treats the phenomena from the view point of price.
7. The most acceptable definition is that of “Professor Lionel Robbins”; The science which studies human behavior as a relationship between end and scarce means which have alternative uses.

From the definition of Professor Lionel Robbins, the following points can be explained:

1. Ends: Ends refers to human wants. They can also be the aims, objectives, goals or desires. These wants are the output of goods and services (commodities). Examples of our basic wants are shelter, clothing and food.

These wants are numerous (limitless, endless, insatiable, infinite or unlimited). They cannot all be satisfied. Human wants vary from person to person, place to place and from time to time.

2. Means: Means refers to economic resources inputs, agents or factors of production with which we can obtain our wants or needs. Eg: Land, labor, capital and entrepreneur.

These means are limited (scarce insufficient) in supply relative to demand for them. They all possess utility can be used for more than one purpose and command a price.

3. Alternative Uses: This means that economic resources have so many competing uses to which they can be put. Eg: A student can choose, to buy a bag or a textbook with the money he has.

These terms above relate to each other in that at a given time the ends (wants) of an individual are many and unlimited that they are impossible to be satisfied all at a time. Since resources (means) are scarce or insufficient in supply uses or competing ways into which the resources could be put.

Despite disagreement about the definition of Economics, Economists agree that Economics is a social science which studies human behavior or man’s activities in relationship to production, exchange, distribution and consumption. All these activities are aimed at satisfying human wants.