Fashion is a term used to describe the styles of clothing worn at any given time. It is an industry that includes the designing, making and selling of clothes and accessories. Fashion changes constantly and is influenced by many factors, including social, cultural and economic ones. Fashion can be described as an aesthetic pursuit and the way a person dresses is often considered to be a reflection of their personality and lifestyle. The concept of fashion has been a subject of debate for centuries, with some historians placing its origin in late medieval times.

Modern Westerners have a wide array of choices in the selection of their clothes and may choose to dress in a style that reflects their interests or expresses their personal identity. Fashion trends typically start when people who have high cultural status, such as movie stars, politicians and musicians, begin wearing new or different types of clothes. These trends then spread to the wider population, and people who like or respect these individuals might also start to wear clothes of a similar style. People who follow the latest fashions are often called fashionistas or fashion victims.

It is a widely held belief that fashion trends are caused by societal change and that designers and manufacturers create them in order to make money. More recent research, however, has indicated that fashion changes are often the result of internal taste mechanisms and that these can sometimes operate independently of societal influences.

The fashion industry is a multibillion dollar global enterprise. Designers and brands produce ready-to-wear collections of clothing, and many of these are displayed in specialized runway shows in Paris, New York City and Milan. More affordable clothing lines are then sold in department stores and retail outlets, as well as being advertised in fashion magazines and on television. The rise of the internet has made it possible for fashion to be marketed and sold around the world instantly.

Although fashion is often thought of as an art, it has its roots in practicalities. People need to dress according to the weather, and clothing is a good way to distinguish oneself from others. Clothing is also a form of identification and tradition: judges wear robes, soldiers wear uniforms, and brides wear white dresses. Fashion is a social phenomenon, and it is important to consider the impact of fashion in human societies.

A fashion trend can be triggered by anything, from a person who begins to wear clothes of a particular style, to the popularity of a particular genre of music or television show. It is therefore difficult to define what makes something a fashion. The direction of a fashion trend is often hard to predict and depends on a number of factors, including social and cultural changes, the economic situation, and the availability of materials. Changing tastes are also an important factor, and this is reflected in the ever-changing range of clothes available. Some fashions fade quickly, while others are more lasting.