Beauty is a property associated with human beings. This could be considered even as a characteristic. Beauty is not only related to human beings. Beauty can be associated with locations, certain concepts, certain things etc as well. This property or characteristic named beauty makes other people happy about it. Any thing beautiful is a joy for others to watch.
The word beauty was originally taken from Greek language. According to the Greek interpretation, the word's meaning was - according to one's hour. This has philosophical implications as it implies that every thing beautiful has to belong to its time. So any one who is trying to look too younger or older for their actual age cannot be considered beautiful!!
Now the concept of beauty is universal. But the way people from one geographical location analyze beauty can be different from the perception of beauty as looked at from some one from a different geographical location. These are the cultural differences of beauty. A beautiful person in American culture may not be the same as that in African culture. A simple example is the weight of the person. In the western culture beauty is synonymous with skinny. But in many parts of Africa and Asia, being fat is considered beautiful. This could be understood in the case of Stone Age man, as a fat person would have a much better chance of surviving a famine. When hunting was the major source of one's income, having a really fat wife would have been the equivalent of riding a Lamborghini in today's world!!
Even today in Mauritania, a country in Africa, girls are fattened to such a degree that they are at risk of getting sick at a very young age. As very fat girls are the only ones who get married easily there, it is a common practice there to force feed the girls to extreme levels.
Most societies considered being fat as beautiful until a century ago. The concept of thin beauty is a very recent phenomenon.
The common saying is that, Beauty is in the eye of the beholder. This phrase defines the subjective nature of beauty to the full extent. As is the case of body weight explained above, people from different cultures tend to look at beauty from different viewpoints.
When it comes to religion, they give more weight to the inner beauty of the person. This usually refers to the character of the person more than his or her looks.
Beauty has mathematical properties too. Beautiful things are usually symmetric and proportional. The Greeks believed that the proportion of the features of any beautiful person must be as per golden ratio. Modern studies have proven that the Greeks ideas on beauty were correct.