Economics

In order to survive we have to fulfil our material need like food clothes and shelter.

To fulfill our material need like food clothes and shelter we human beings have to engage in certain kind of activities.(like gathering food , cultivation of food, buying or exchange food for some other item.)
Just like food we have many other material need in our life. But our time , energy. Resource is limited compared to large amount/type of need we have to fullfill.
So we have to take decision. How to use our limited Resource to satisfy our unlimited want.
In simple word for an individual how to spend the monthly salary so that maximum satisfaction or benefit it obtained from it.

For a producer or business owner the problem will be how to produce a product so that it is produced efficiently at low cost.

For a country or government it is how to/ spend the money(for health/ education road, hospital or making bombs parks etc
) so that the nation as a whole makes the most out of it.
Economics is basically the study of possible choices these individuals, company, and government have in making decisions and possible outcomes of those decision.