The six basic principles of sustainable development are:
(i) To respect and care all forms of life.
(ii) To improve the quality of human life.
(iii) To conserve the earth's vitality and diversity. 
(iv) To minimise the depletion of natural resources.
(v) To change the personal attitude and malpractices towards the environment.
(vi) To encourage communities to care for their own environment.

Natural resources are classified into different groups on different basis.
These are:
(i) On the basis of their level of development and use:
(a) Actual Resources and
(b) Potential Resources.
(ii) On the basis of their origin :
(a) Abiotic and
(b) Biotic Resources.
(iii) On the basis of their distribution:
(a) Ubiquitous Resources and
(b) Localised Resources.
(iv) On the basis of stock:
(a) Renewable resources and
(b) Non-renewable resources.

The distinguish between natural and human resources are as follows;

Any substance used for production and is market-oriented has an economic value.
For example cotton is used in industries to produce textiles and other goods, so cotton has economic value. However, moral values and love for friends and family do not have economic value but have social value.

Resources used in home
(i) Natural resources in home:
1. Air
2. Water
3. Minerals like: salt, sugar etc.
(ii)Human-made resources in home are:
1. Air cooler
2. Refrigerator
Resources used in classroom
(i) Natural resources in classroom are:
1. Air
2. Water
3. Solar energy/sunlight
(ii) Human-made resources in classroom are:
1. Desks
2. Furniture
3. Chalkboard

(i) The resource here is water.
(ii) Water is an important resource as it is not only necessary for our daily work, but also needed to produce electricity. The life of other living beings also depends on it.
If this resource disappears from the earth, then we will face the following problems:
(a) All life will disappear from earth.
(b) No plants and trees will grow in the absence of water.
(c) All the vegetation would dry up.
(d) Allthe animals and human beings are dependent on plants for oxygen and food. So they will not get any food and the level of carbon dioxide will increase in atmosphere, hence animals and human beings would die.
(e) All the human activities would come to an end.
(f) No industry would exist on the surface of the earth.
(g) The earth would completely dry up and get scorched.

Wind power is the fastest growing energy source in the world. A wind turbine works the opposite of a fan. Instead of using electricity to make wind, a turbine uses wind to produce electricity.
The wind turns the blades, which spin a shaft, which connects to a generator and produces electricity. The electricity is sent through transmission and distribution lines to a substation, then on to homes, business houses and schools. Wind turbines do not have any adverse effect on the environment. That's why wind power is gaining popularity. It is also becoming economically competitive with more conventional power sources-a fact that's greatly improving its prospects as a viable energy source.

Raju and his friends made packets and shopping bags out of old newspaper and discarded clothes and basket from bamboo sticks.They also promised each other to make proper use of resources and decided to stop wastage of these resources.

The distribution of natural resources depends upon a number of physical factors like terrain, climate and altitude, which is varied, so the distribution of resources is unequal all over the earth.

Resource Conservation : Resource conservation means using resources carefully and giving them time to get renewed.
Sustainable Development: Balancing the need to use the resources at present and also conserving them for the future is called sustainable development.

There are many reasons for treating humans as a resource.
Some of the important reasons are :
(i) Human resource refers to the number (quantity) and abilities (mental and physical) of the people.
(ii) It is the human ability which transfers physical materials into valuable resources.
(iii) People can make full use of nature if they have skills and knowledge.
(iv) Education and health are two important factors that make man a precious resource.