Because it can be a subjective experience, it is often said that "beauty is in the eye of the beholder." Often, given the observation that empirical observations of things that are considered beautiful often align among groups in consensus, beauty has been stated to have levels of objectivity and partial subjectivity which are not fully subjective in their aesthetic judgement. Ugliness is the opposite of beauty.

The word "beauty" is often used as a countable noun to describe a beautiful woman, an excellent example of something, or a pleasing feature of something.

Researchers have found that good-looking students get higher grades from their teachers than students with an ordinary appearance. Some studies using mock criminal trials have shown that physically attractive "defendants" are less likely to be convicted—and if convicted are likely to receive lighter sentences—than less attractive ones (although the opposite effect was observed when the alleged crime was swindling, perhaps because jurors perceived the defendant's attractiveness as facilitating the crime). Studies among teens and young adults, such as those of psychiatrist and self-help author Eva Ritvo show that skin conditions have a profound effect on social behavior and opportunity.

How much money a person earns may also be influenced by physical beauty. One study found that people low in physical attractiveness earn 5 to 10 percent less than ordinary-looking people, who in turn earn 3 to 8 percent less than those who are considered good-looking. In the market for loans, the least attractive people are less likely to get approvals, although they are less likely to default. In the marriage market, women's looks are at a premium, but men's looks do not matter much.

Conversely, being very unattractive increases the individual's propensity for criminal activity for a number of crimes ranging from burglary to theft to selling illicit drugs. Discrimination against others based on their appearance is known as lookism.

The characterization of a person as “beautiful”, whether on an individual basis or by community consensus, is often based on some combination of inner beauty, which includes psychological factors such as personality, intelligence, grace, politeness, charisma, integrity, congruence and elegance, and outer beauty (i.e. physical attractiveness) which includes physical attributes which are valued on an aesthetic basis.

Standards of beauty have changed over time, based on changing cultural values. Historically, paintings show a wide range of different standards for beauty. However, humans who are relatively young, with smooth skin, well-proportioned bodies, and regular features, have traditionally been considered the most beautiful throughout history.