What is food? And give its importance.
Man must eat in order to live; therefore, one of the most important problems man has is that of always being certain that he will have enough to eat when he needs it.
At first, man did not have any way to control his food supply. For his food he uses the plants and animals as he found them. He ate roots, seeds, berries, eggs, fruits, honey, and the meat of animals. Probably the food were not cooked or prepared in any special way.
Even in small societies special knowledge was necessary for hunting and fishing, for preparing the food, and for preserving food for use at a later time.
As we have said, at first man had no way to control his food supply. When he had killed all the animals in one place and all the natural foods had been used, he had to move to another region to find new sources of food. If there was no rain, or if the weather was too hot or too cold, plants would not grow and man had little or no food. However, man gradually learned ways to grow plants and raise animals himself. From that time on, he was not so dependent on natural conditions and did not have to worry so much about always having enough food.
The kinds of plants which are raised by men are different in each geographical or climatic region. In the colder regions, very few plants can be grown; in the warmer parts of the world, great varieties of plants are found, but there is still some specialization in particular kinds of plants. For example, in Asia, rice is the most important crop. In the New World, the major grain is corn (or maize). In Europe and North Africa, wheat, oats, and barley are grown. In the tropical regions of the world, many kinds of fruit grow naturally or are raised by men.
To a certain extent, the kinds of animals raised by man were also determined by climate and geography, or simply by the kinds of animals available in one particular area. For example, cows, sheep, and goats were found naturally only in particular areas of the world, and only the people living in those areas were able to use those particular animals for food or for other purposes. Cows, sheep, and goats are now common in all parts of the world. As man has learned more about plants and animals, the production of food has become a more technical and specialized process. However, there are still many areas of the world where plants and animals are raised in such the same ways as were used thousands of years ago.