For the past few days in economics class I've learnt about the term "opportunity cost". We all have to make choices in our life and the procedure is to sacrifice a certain thing in order to have the other. Opportunity cost is defined where the next best alternative is forgone. For example, a small spot of land in Shah Alam can be used as a playground or a shopping complex. The advantages of having a shopping complex would really benefit the consumers. This is because they get more entertainment and  more goods and services to satisfy. Where as having a playground will promote healthy lifestyle to the society. The government will have to decide which one of them would give the most benefit to the society and the next best alternative will be forgone. Economics Goods are goods that has an opportunity cost. However, Free Goods are goods that has no opportunity cost. They are so called " Natural resources".

Besides, I've learnt about PPC (Production Possibility Curve).Let me show you some graphs about PPC, to give you a clear image about it. 

This is a similar concept of a PPC. As you can see, the line, what I called the “z”, shows the maximum number of output that can be produced by a given number of inputs (Factors of production). The Y region is the area beyond the line that can’t be fulfilled. Unless, there are more resources found in order to produce. The X region is where the economy goes into recession (slump). This part is when the resources are not utilized into its maximum potential. 

To go beyond or below the line, another graph is shown here to show why there is a shift for the line itself. 

When the line A moves from point A to Point C, the economy is growing. More goods and services are produced than before. What makes an economy grow? The government might impose fiscal policy into the economy in order to increase growth. By reducing the level of taxes and increasing government expenditure. For example, Income tax will be lowered and consumers are able to purchase more goods and services than before due to higher disposable income. A government might subsidy advanced technology to improve the quality of goods and services which attracts more consumers to purchase them. As more consumers buy these goods, more money will be circulating in the economy. Therefore, aggregate demand increases which makes the living standards higher.Well, I hope my explanation is right: P

When the point moves from point A to Point B, the economy is having a Recession (slump).  Goods and services can’t reach its maximum output due to many factors affecting it. One example might be Inflation. The price of goods and services are high which made consumers not to purchase these goods and services. The producers will cut down their production in order to not make any loses if possible.

A PPC is used to Show:

• Economy growth (positive/negative)
• the change in living standards
• efficiency 
• technological progress
• Opportunity cost between two different G&S produced

The three graphs I've learnt about PPC. 

All three of them gives different characteristics. 

  The concave graph: 

• low efficiency
• decreasing economies of scale
• increasing opportunity cost  

  The convex graph:

• increasing returns of scale 
• high efficiency 
• decreasing opportunity cost  

  The indirectly proportional graph: 

• constant return of scale 
• opportunity cost constant.(well not really for this particular graph but just to get the concept of it)