Civilization is commonly believed to have started with the development of agriculture. This development allowed roaming tribes of human beings to settle onto one location and have a relatively stable food source, which allowed humans to spend time sitting around and thinking of stuff as opposed to hunting all damn day.
Some regard civilization as a good thing, I for one am not all gung-ho about returning to the state of nature, while others think that civilization is evil, see Rousseau and Freud.

In regards to Civilization as a computer game, it's a very nice computer game, an excellent waste of time, perhaps second only to masturbation, especially if you're into the whole world domination thing. And for your viewing pleasure, I wish to present The Everything Civilopedia, an encyclopedia of all things Civilization related!

Advances
Throughout the game, the player devotes resources to scientific research to develop a roving band of settlers with primitive knowledge to a globe-spanning empire in the space age.

Advanced Flight
Alphabet
Astronomy
Atomic Theory
Automobile
Banking
Bridge Building
Bronze Working
Ceremonial Burial
Chemistry
Chivalry
Code of Laws
Communism
Computers
Conscription
Construction
The Corporation
Currency
Combustion
The Democracy
Electricity
Electronics
Engineering
Explosives
Feudalism
Flight
Fusion Power
Genetic Engineering
Gunpowder
Horseback Riding
Industrialization
Invention
Iron Working
Labor Union
Literacy
Magnetism
Mapmaking
Masonry
Mass Production
Mathematics
Medicine
Metallurgy
The Monarchy
Mysticism
Navigation
Nuclear Fission
Nuclear Power
Philosophy
Physics
Plastics
Pottery
Railroad
Recycling
Refining
Religion
The Republic
Robotics
Rocketry
Space Flight
Steam Engine
Steel
Superconductor
Theory of Gravity
Trade
University