I. The definition of culture:

There are different sentences, people define the culture:

- "By culture we mean all those historically created designs for living, explicit and implicit, rational, irrational, and non-rational, which exist at any given time as potential guides for the behavior of men."

"Culture...consists in those patterns relative to behavior and the products of human action which may be inherited, that is, passed on from generation to generation independently of the biological genes" (p. 8).

"Culture has been defined in a number of ways, but most simply, as the learned and shared behavior of a community of interacting human beings" (p. 169).

II. The definition of the first, the second and the third World.

1.    The first World:

To discuss about the term "First World", people will think of developed, capitalist, industrial countries, and a bloc of countries aligned with the United States after World War II. For example: North America, Western Europe, Japan, Australia and their allies 

The term – first World mostly tries to describe the top end of the evolution of countries. Nations with the most advanced economy, highest standard of living, the most advanced technology, the greatest influence in the world.

2.    The second World:

That refers to the former of communist-socialist, industrial states, such as Russia, Eastern Europe and some of the Turk States) as well as China, and their allies.

3.    The third World:

The term Third World occurred during the Cold War to define countries that remained non-aligned with either NATO, or the Communist. When we talk about the third World, we will think of the poorest nations in the World, namely Africa, Latin America, Oceania and Asia. Moreover, the term Third World includes as well capitalist and communist

Reference:

http://www.carla.umn.edu/culture/definitions.html

Kluckhohn, C., & Kelly, W.H. (1945). The concept of culture. In R. Linton (Ed.). The Science of Man in the World Culture. New York. (pp. 78-105).

Parson, T. (1949). Essays in Sociological Theory. Glencoe, IL.

Useem, J., & Useem, R. (1963). Human Organizations, 22(3).

http://www.nationsonline.org/oneworld/third_world_countries.htm